Replace Prow Tide with GitHub merge queue workflows

This PR replaces the Prow Tide mechanism with native GitHub workflows
and merge queue functionality, providing equivalent approval and merge
automation without external infrastructure.

1. **approval-labels.yaml**: Handles /lgtm and /approve commands
   - Adds/removes lgtm and approved labels via PR comments
   - Permission checking using GitHub API
   - Only users with write access can approve

2. **hold-label.yaml**: Handles /hold and /unhold commands
   - Allows maintainers and PR authors to block PRs from merging
   - Adds/removes do-not-merge/hold label

3. **wip-label.yaml**: Automatic WIP detection
   - Detects [WIP], WIP:, [Draft], draft status, or 🚧 in PR titles
   - Auto-manages do-not-merge/work-in-progress label

4. **release-notes-label.yaml**: Release note enforcement
   - Requires release-note, release-note-action-required, or release-note-none
   - Blocks merge if missing release note label

5. **needs-rebase-label.yaml**: Merge conflict detection
   - Automatically detects merge conflicts
   - Manages needs-rebase label

6. **merge-readiness.yaml**: Required status check
   - Verifies both lgtm and approved labels are present
   - Blocks if any do-not-merge/* or needs-* labels exist
   - Single source of truth for merge eligibility

- **.github/github-merge-queue.md**: Complete documentation
  - Command reference for /lgtm, /approve, /hold
  - Workflow diagrams and architecture
  - Migration guide from Prow Tide
  - Setup instructions for merge queue

- **ci.yaml**: Removed unnecessary job dependencies
  - Unit tests, linting, and other checks now run in parallel
  - No longer wait for build job unnecessarily
  - Faster feedback on PRs

- **kind-e2e.yaml**: Added CI check dependency
  - E2E tests now wait for CI checks to pass on PRs
  - Prevents wasteful E2E runs on broken code
  - Push/merge_group events run immediately without waiting

-  Event-driven (immediate) vs polling (2m delay)
-  No infrastructure to maintain
-  Native GitHub UI integration
-  Simpler permission model
-  Better visibility with GitHub checks
-  Works with GitHub merge queue

- All existing Prow commands work identically: /lgtm, /approve, /hold
- Blocking labels have same effect: do-not-merge/*, needs-*
- Permission model uses GitHub repository access (write/admin)

Co-authored-by: Claude <claude@anthropic.com>

Author: anithapriyanatarajan

.github/github-merge-queue.md

@@ -0,0 +1,340 @@
+# GitHub Merge Queue Setup
+
+This document describes the GitHub-based approval and merge system that replaces Prow Tide.
+
+## Overview
+
+The repository now uses GitHub workflows and merge queue instead of Prow Tide for managing PR approvals and merges. This provides:
+
+- Label-based approval system via comment commands
+- Required status checks for merge readiness
+- Automatic merging via GitHub merge queue
+
+## Workflow Diagram
+
+```mermaid
+flowchart TD
+    Start([PR Created/Updated]) --> AutoChecks{Automatic Checks}
+    
+    AutoChecks --> WIP[Check WIP Status]
+    AutoChecks --> ReleaseNote[Check Release Note Label]
+    AutoChecks --> Rebase[Check Merge Conflicts]
+    
+    WIP -->|WIP detected| WIPLabel[Add: do-not-merge/work-in-progress]
+    WIP -->|Ready| WIPRemove[Remove: do-not-merge/work-in-progress]
+    
+    ReleaseNote -->|Missing label| RNLabel[Add: do-not-merge/release-note-label-needed]
+    ReleaseNote -->|Has label| RNRemove[Remove: do-not-merge/release-note-label-needed]
+    
+    Rebase -->|Conflicts| RebaseLabel[Add: needs-rebase]
+    Rebase -->|Clean| RebaseRemove[Remove: needs-rebase]
+    
+    WIPLabel --> ManualReview
+    WIPRemove --> ManualReview
+    RNLabel --> ManualReview
+    RNRemove --> ManualReview
+    RebaseLabel --> ManualReview
+    RebaseRemove --> ManualReview
+    
+    ManualReview{Manual Review} -->|Reviewer comments /lgtm| LGTMLabel[Add: lgtm]
+    ManualReview -->|Maintainer comments /approve| ApprovedLabel[Add: approved]
+    ManualReview -->|Anyone comments /hold| HoldLabel[Add: do-not-merge/hold]
+    
+    LGTMLabel --> MergeCheck
+    ApprovedLabel --> MergeCheck
+    HoldLabel --> MergeCheck
+    
+    MergeCheck{Merge Readiness Check}
+    
+    MergeCheck -->|Has lgtm + approved<br/>No blocking labels| Ready[✅ Status: PASS]
+    MergeCheck -->|Missing lgtm or approved| NotReady[❌ Status: FAIL<br/>Missing required labels]
+    MergeCheck -->|Has blocking labels| Blocked[❌ Status: FAIL<br/>Has blocking labels]
+    
+    Ready --> MergeQueue[Add to Merge Queue]
+    NotReady --> Wait[Wait for approvals]
+    Blocked --> Wait
+    
+    Wait --> ManualReview
+    
+    MergeQueue --> FinalChecks{All CI Checks Pass?}
+    FinalChecks -->|Yes| Merge([🎉 PR Merged])
+    FinalChecks -->|No| Failed([❌ Merge Failed])
+    
+    style Start fill:#e1f5ff
+    style Merge fill:#d4edda
+    style Failed fill:#f8d7da
+    style Ready fill:#d4edda
+    style NotReady fill:#fff3cd
+    style Blocked fill:#f8d7da
+    style MergeQueue fill:#cfe2ff
+```
+
+### Key Points
+- **Green boxes** = Success states
+- **Yellow boxes** = Waiting/pending states  
+- **Red boxes** = Blocked/failed states
+- **Blue boxes** = Active processing
+
+## Approval System
+
+### Commands
+
+Maintainers with **write** access can use the following commands in PR comments:
+
+#### `/lgtm` - Looks Good To Me
+Adds the `lgtm` label to indicate code review approval.
+
+```
+/lgtm
+```
+
+To remove the label:
+```
+/lgtm cancel
+```
+
+**Restrictions**: 
+- Requires write access to the repository
+- ⚠️ PR authors and co-authors cannot `/lgtm` or `/approve` their own PRs
+
+#### `/approve` - Final Approval
+Adds the `approved` label to indicate final approval for merge.
+
+```
+/approve
+```
+
+To remove the label:
+```
+/approve cancel
+```
+
+**Restrictions**: 
+- Requires write access to the repository  
+- ⚠️ PR authors and co-authors cannot `/lgtm` or `/approve` their own PRs
+
+#### `/hold` - Hold PR from Merging
+Adds the `do-not-merge/hold` label to block a PR from merging. Both maintainers and PR authors can use this command.
+
+```
+/hold
+```
+
+To remove the hold:
+```
+/unhold
+```
+or
+```
+/hold cancel
+```
+
+### Permissions
+
+- Only users with **write** access to the repository can use approval commands
+- Commands must be placed at the start of a comment
+- The bot will react with emoji to indicate status:
+  - 👀 (eyes) - Processing command
+  - 👍 (+1) - Label added successfully
+  - 👎 (-1) - Label removed successfully
+  - 😕 (confused) - Insufficient permissions
+
+## Automatic Label Management
+
+Several workflows automatically manage labels based on PR state:
+
+### Work in Progress (WIP)
+- **Trigger**: PR title contains `[WIP]`, `WIP:`, `[Draft]`, `Draft:`, or 🚧 emoji, or PR is marked as draft
+- **Action**: Adds `do-not-merge/work-in-progress` label
+- **Resolution**: Remove WIP indicators from title or convert from draft to ready
+
+### Release Notes
+- **Trigger**: PR is missing a release note label
+- **Action**: Adds `do-not-merge/release-note-label-needed` label
+- **Resolution**: Add one of these labels manually, or use commands:
+  - `release-note` - For user-facing changes
+  - `release-note-action-required` - For breaking changes requiring user action
+  - `release-note-none` - For internal changes with no user impact
+  - **Commands**: `/release-note`, `/release-note-action-required`, `/release-note-none`
+  - **Permissions**: ⚠️ **PR author ONLY** (following Prow's behavior - this ensures the author takes responsibility for documenting their changes)
+
+### Merge Conflicts
+- **Trigger**: PR has merge conflicts with base branch
+- **Action**: Adds `needs-rebase` label
+- **Resolution**: Rebase or merge the base branch to resolve conflicts
+
+### Hold
+- **Trigger**: Someone comments `/hold`
+- **Action**: Adds `do-not-merge/hold` label
+- **Resolution**: Comment `/unhold` or `/hold cancel`
+- **Permissions**: PR author OR maintainers with write access
+
+## Blocking Labels
+
+The following labels will block a PR from merging (checked by the Merge Readiness workflow):
+
+- `do-not-merge/hold` - Manual hold requested
+- `do-not-merge/invalid-owners-file` - OWNERS file is invalid
+- `do-not-merge/release-note-label-needed` - Missing release note label
+- `do-not-merge/requires-unreleased-pipelines` - Depends on unreleased Tekton pipelines
+- `do-not-merge/work-in-progress` - PR is still in progress
+- `needs-ok-to-test` - PR needs approval to run tests
+- `needs-rebase` - PR has merge conflicts
+
+
+
+## Enabling Auto-Merge with Merge Queue
+
+Once both required labels are present:
+
+1. The "Merge Readiness Check" status will turn green
+2. The PR can be added to the merge queue
+3. Enable auto-merge on the PR to have it automatically merge when ready
+
+### Repository Settings
+
+To enable merge queue for the repository:
+
+1. Go to **Settings** → **General** → **Pull Requests**
+2. Enable **Allow auto-merge**
+3. Go to **Settings** → **Branches** → **Branch protection rules** for your main branch
+4. Enable **Require merge queue**
+5. Add **Merge Readiness Check** as a required status check
+6. Configure merge queue settings:
+   - Minimum PRs to merge: 1 (or as desired)
+   - Maximum PRs to merge: 5 (or as desired)
+   - Merge method: Squash, merge commit, or rebase (as per project preference)
+
+## Workflow Files
+
+All merge automation workflows are located in `.github/workflows/` with the `pr_` prefix.
+
+### [`pr_approval-labels.yaml`](workflows/pr_approval-labels.yaml)
+Handles `/lgtm` and `/approve` commands in PR comments. Manages label addition and removal based on user permissions.
+- **Permissions**: Requires write access to the repository
+- **Commands**: `/lgtm`, `/lgtm cancel`, `/approve`, `/approve cancel`
+- **Restrictions**: PR authors and co-authors cannot approve their own PRs (prevents self-approval)
+
+### [`pr_hold-label.yaml`](workflows/pr_hold-label.yaml)
+Handles `/hold` and `/unhold` commands. Allows maintainers and PR authors to block/unblock PRs from merging by adding/removing the `do-not-merge/hold` label.
+- **Permissions**: PR author or users with write access
+- **Commands**: `/hold`, `/unhold`, `/hold cancel`
+
+### [`pr_wip-label.yaml`](workflows/pr_wip-label.yaml)
+Automatically detects work-in-progress PRs by checking for:
+- PR titles starting with `[WIP]`, `WIP:`, `[Draft]`, or `Draft:`
+- Draft PR status
+- 🚧 emoji in title
+
+Adds/removes `do-not-merge/work-in-progress` label accordingly.
+
+### [`pr_release-notes-label.yaml`](workflows/pr_release-notes-label.yaml)
+Checks for release note labels on PRs. Adds `do-not-merge/release-note-label-needed` if missing one of:
+- `release-note` - User-facing changes
+- `release-note-action-required` - Requires action from users
+- `release-note-none` - No user-facing changes
+
+**NEW**: Also supports comment commands for easier label management:
+- **Commands**: `/release-note`, `/release-note-action-required`, `/release-note-none`
+- **Permissions**: ⚠️ **PR author ONLY** (matches Prow's release-note plugin behavior)
+- **Rationale**: Only the PR author can set release note labels to ensure they take responsibility for documenting their changes
+- **Features**: Automatically removes other release-note labels when applying a new one
+
+### [`pr_needs-rebase-label.yaml`](workflows/pr_needs-rebase-label.yaml)
+Automatically detects merge conflicts and adds/removes the `needs-rebase` label when conflicts are present.
+
+### [`pr_merge-readiness.yaml`](workflows/pr_merge-readiness.yaml)
+Provides a required status check that verifies both `lgtm` and `approved` labels are present and no blocking labels exist.
+
+## Migration from Prow
+
+This system replaces the Prow Tide configuration with native GitHub functionality:
+
+| Prow Tide | GitHub Workflows |
+|-----------|------------------|
+| `/lgtm` command | `/lgtm` command (via `pr_approval-labels.yaml`) |
+| `/approve` command | `/approve` command (via `pr_approval-labels.yaml`) |
+| `/hold` command | `/hold` command (via `pr_hold-label.yaml`) |
+| Release note plugin | Release note workflow (via `pr_release-notes-label.yaml`) with `/release-note-*` commands |
+| Tide merge pool | GitHub Merge Queue |
+| Tide status contexts | Merge Readiness Check |
+| Automatic merging | Auto-merge + Merge Queue |
+
+### Key Differences from Prow Tide
+
+#### Architecture
+- **Prow Tide**: Centralized service running on Kubernetes cluster, polls GitHub API for PRs matching criteria
+- **GitHub Workflows**: Distributed event-driven workflows, triggered by GitHub webhooks on PR events
+- **Result**: Lower latency (immediate response vs polling), no infrastructure to maintain
+
+#### Label Management
+- **Prow Tide**: Plugins (lgtm, approve, hold, wip) managed by central Prow plugins
+- **GitHub Workflows**: Individual workflows handle each command independently
+- **Result**: More modular, easier to customize individual behaviors
+
+#### Merge Process
+- **Prow Tide**: 
+  - Batches multiple PRs together for testing
+  - Maintains merge pool with sync loop (default: 2m)
+  - Tests PRs together, merges if batch passes
+  - Bisects on failure to find culprit
+- **GitHub Merge Queue**:
+  - Tests each PR individually or in configurable groups
+  - Queue-based approach with configurable merge strategies
+  - Native GitHub UI for queue visibility
+  - No separate infrastructure needed
+- **Result**: Similar reliability, simpler setup, better UI
+
+#### Permission Model
+- **Prow Tide**: Uses GitHub team membership and OWNERS files
+- **GitHub Workflows**: Uses GitHub's native repository permissions (read/write/admin)
+- **Result**: More straightforward, one permission system to manage
+
+#### Status Checks
+- **Prow Tide**: Multiple required contexts, complex configuration
+- **GitHub Workflows**: Single "Merge Readiness Check" workflow
+- **Result**: Simpler to understand, single source of truth
+
+#### Commands
+- **Prow Tide**: Fixed set of commands defined in plugins config
+- **GitHub Workflows**: Flexible, can add new commands easily by creating new workflows
+- **Result**: More extensible and customizable
+
+#### What's the Same
+✅ `/lgtm` and `/approve` commands work identically  
+✅ `/hold` blocks merging  
+✅ `do-not-merge/*` labels prevent merging  
+✅ Automatic WIP detection  
+✅ Release note label enforcement  
+✅ Merge conflict detection  
+✅ Permission-based access control  
+
+#### What's Different
+⚠️ **No batch merging** - GitHub merge queue tests PRs individually or in smaller groups  
+⚠️ **No OWNERS file** - Uses GitHub repository permissions instead  
+⚠️ **Different UI** - GitHub PR UI instead of Prow dashboard  
+⚠️ **Faster response** - Event-driven instead of polling (2m sync period)  
+⚠️ **Simpler setup** - No Prow infrastructure needed  
+
+#### Migration Considerations
+- **OWNERS files**: If you rely on OWNERS files for approval, you'll need to migrate to GitHub CODEOWNERS
+- **Batch testing**: If you need to test multiple PRs together, configure merge queue groups
+- **Custom plugins**: Any custom Prow plugins need to be reimplemented as GitHub workflows
+- **Tide configuration**: Context requirements → Branch protection rules
+- **Bot accounts**: Replace Prow bot token with GitHub Actions bot or app
+
+## Troubleshooting
+
+### Commands not working
+- Verify you have write access to the repository
+- Ensure the command is at the start of the comment
+- Check workflow run logs in the Actions tab
+
+### Merge Readiness Check failing
+- Verify both `lgtm` and `approved` labels are present
+- Check the workflow logs for detailed status
+
+### Auto-merge not triggering
+- Ensure merge queue is enabled in repository settings
+- Verify all required status checks are passing
+- Check that auto-merge is enabled on the PR

.github/workflows/ci.yaml

@@ -31,7 +31,6 @@ jobs:
 
   unit-tests:
     name: Unit Tests
-    needs: [build]
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8  # v6.0.1
@@ -44,7 +43,6 @@ jobs:
 
   linting:
     name: Linting
-    needs: [build]
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8  # v6.0.1
@@ -73,7 +71,6 @@ jobs:
 
   check-licenses:
     name: License Check
-    needs: [build]
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8  # v6.0.1
@@ -87,7 +84,6 @@ jobs:
 
   ko-resolve:
     name: Ko Resolve (Multi-arch)
-    needs: [build]
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8  # v6.0.1