ci: add Azure workflow scoping OIDC tests via azureoidc build tag

Addresses review feedback on PR #1794:
#1794 (comment)

Replaces the brittle enumerated `-run '^(TestA|TestB)$'` regex with a
new `azureoidc` build tag. Tests opt in by adding the tag, so adding
or removing OIDC-compatible tests no longer requires editing the
workflow.

- TerraformAzureContainerAppExample and TerraformAzureKeyVaultExample
  carry `azure || azureoidc`, so they remain part of the default
  `azure` build while also being selectable via the narrower OIDC tag.
- Workflow runs `go test -tags azureoidc ./test/azure/...`.

Author: james00012

.github/workflows/azure-integration-tests.yml

@@ -24,7 +24,9 @@ on:
 
 concurrency:
   group: azure-integration-tests-${{ github.ref }}
-  cancel-in-progress: true
+  # Don't cancel in-flight runs; tests provision real resources and rely
+  # on `defer terraform.Destroy` for cleanup.
+  cancel-in-progress: false
 
 jobs:
   azure-integration-tests:
@@ -78,11 +80,10 @@ jobs:
         run: |
           set -o pipefail
           mkdir -p /tmp/logs
-          # Scope: OIDC-compatible examples only (AzureRM provider >= 3.7).
-          # Examples on AzureRM 2.x cannot authenticate via OIDC and are
-          # gated behind a follow-up provider-upgrade effort.
-          go test -v -p 1 -tags azure -count=1 -timeout 45m \
-            -run '^(TestTerraformAzureContainerAppExample|TestTerraformAzureKeyVaultExample)$' \
+          # Runs only tests tagged `azureoidc`. Opt a test in by adding
+          # `//go:build azure || azureoidc` to its file. AzureRM 2.x examples
+          # cannot use OIDC and stay on the default `azure` tag.
+          go test -v -p 1 -tags azureoidc -count=1 -timeout 45m \
             ./test/azure/... 2>&1 | tee /tmp/logs/azure-integration-tests.log
 
       - name: Upload test logs

test/azure/terraform_azure_container_apps_example_test.go

@@ -1,5 +1,5 @@
-//go:build azure
-// +build azure
+//go:build azure || azureoidc
+// +build azure azureoidc
 
 package test_test
 

test/azure/terraform_azure_keyvault_example_test.go

@@ -1,5 +1,5 @@
-//go:build azure
-// +build azure
+//go:build azure || azureoidc
+// +build azure azureoidc
 
 package test_test