fix(ci): Use Dependabot to update flake.lock and GitHub Actions

Author: mrjones2014

.github/dependabot.yml

@@ -0,0 +1,28 @@
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
+      day: friday
+    cooldown:
+      default-days: 14
+    commit-message:
+      prefix: chore
+      include: scope
+    groups:
+      actions-minor-patch:
+        update-types: [minor, patch]
+  - package-ecosystem: nix
+    directory: /
+    schedule:
+      interval: weekly
+      day: friday
+    cooldown:
+      default-days: 14
+    commit-message:
+      prefix: chore
+      include: scope
+    groups:
+      flake-inputs:
+        patterns: ["*"]

.github/workflows/check.yml

@@ -4,18 +4,16 @@ on:
     branches: [master, v3]
   pull_request:
 jobs:
-  check-lua:
+  checks:
     name: Run Checks (${{ matrix.neovim-version }})
     runs-on: ubuntu-latest
     strategy:
       matrix:
         neovim-version: [ci, ci-nightly]
       fail-fast: false
     steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-      - name: Install Nix
-        uses: cachix/install-nix-action@v27
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v27
         with:
           nix_path: nixpkgs=channel:nixos-unstable
       - name: Setup Cachix
@@ -29,3 +27,16 @@ jobs:
         run: nix develop .#${{ matrix.neovim-version }} --command just typecheck
       - name: Run tests
         run: nix develop .#${{ matrix.neovim-version }} --command just test
+  dependabot-auto-merge:
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+      contents: write
+    if: ${{ github.event.pull_request.user.login == 'dependabot[bot]' && github.event_name == 'pull_request' }}
+    steps:
+      - run: |
+          gh pr review --approve "$PR_URL"
+          gh pr merge --squash --auto "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GITHUB_TOKEN: ${{ secrets.GH_PAT_TOKEN }}