fix(ci): Correct and improve Ubuntu version sync workflow (#14238)

This PR addresses several issues in the `Ubuntu Version Sync` workflow
to improve its reliability and clarity.

The workflow was previously failing due to a bash syntax error and was
incorrectly applying Dockerfile checks to project-specific files.

Key changes:

- **Corrected Bash Syntax:** Fixed the syntax for associative array
iteration in the `run` step, resolving the `Unexpected symbol: ' @'`
error.
- **Scoped Dockerfile Checks:** The synchronization check for
Dockerfiles is now strictly limited to the `infra/` directory. This
prevents the workflow from failing on PRs that only modify Dockerfiles
within `projects/`.
- **Improved Workflow Name:** Renamed the workflow to `Ubuntu Version
Sync Check` for better readability in PR status checks, instead of
displaying the raw filename.

Author: hunsche

.github/workflows/ubuntu_version_sync.yml

@@ -14,15 +14,19 @@
 #
 ################################################################################
 
-name: 'Ubuntu Version Sync'
+name: 'Ubuntu Version Sync Check'
 
 on:
   pull_request:
     types: [opened, synchronize, reopened]
 
 jobs:
   check-sync:
+    name: Ubuntu File Synchronization Check
     runs-on: ubuntu-latest
+    env:
+      BASE_SHA: ${{ github.event.pull_request.base.sha }}
+      HEAD_SHA: ${{ github.event.pull_request.head.sha }}
     steps:
     - name: 'Checkout code'
       uses: actions/checkout@v4
@@ -34,7 +38,7 @@ jobs:
       run: |
         set -e
         
-        MODIFIED_FILES=$(git diff --name-only ${{ github.event.pull_request.base.sha }}...${{ github.event.pull_request.head.sha }})
+        MODIFIED_FILES=$(git diff --name-only $BASE_SHA...$HEAD_SHA)
         echo "Checking for synchronized file changes..."
         echo "Modified files in this PR:"
         echo "$MODIFIED_FILES"
@@ -63,27 +67,27 @@ jobs:
         VERSIONS=("ubuntu-20-04" "ubuntu-24-04")
 
         # Check Dockerfiles
-        for legacy_file in "${{!LEGACY_DOCKERFILES[@]}}"; do
-          if echo "$MODIFIED_FILES" | grep -q "^${legacy_file}$"; then
+        for legacy_file in "${!LEGACY_DOCKERFILES[@]}"; do
+          if [[ "${legacy_file}" == infra/* ]] && echo "$MODIFIED_FILES" | grep -q "^${legacy_file}$"; then
             echo "Legacy file changed: $legacy_file. Verifying counterparts..."
-            for version in "${{VERSIONS[@]}}"; do
-              pattern=${{LEGACY_DOCKERFILES[$legacy_file]}}
-              versioned_file="${{pattern/{{version}}/$version}}"
-              if ! echo "$MODIFIED_FILES" | grep -q "^${{versioned_file}}$"; then
+            for version in "${VERSIONS[@]}"; do
+              pattern="${LEGACY_DOCKERFILES[$legacy_file]}"
+              versioned_file="${pattern/\{version\}/$version}"
+              if ! echo "$MODIFIED_FILES" | grep -q "^${versioned_file}$"; then
                 ERRORS+="\n- Legacy file '${legacy_file}' was changed, but its counterpart '${versioned_file}' was not."
               fi
             done
           fi
         done
 
         # Check Scripts
-        for legacy_file in "${{!LEGACY_SCRIPTS[@]}}"; do
+        for legacy_file in "${!LEGACY_SCRIPTS[@]}"; do
           if echo "$MODIFIED_FILES" | grep -q "^${legacy_file}$"; then
             echo "Legacy script changed: $legacy_file. Verifying counterparts..."
-            for version in "${{VERSIONS[@]}}"; do
-              pattern=${{LEGACY_SCRIPTS[$legacy_file]}}
-              versioned_file="${{pattern/{{version}}/$version}}"
-              if ! echo "$MODIFIED_FILES" | grep -q "^${{versioned_file}}$"; then
+            for version in "${VERSIONS[@]}"; do
+              pattern="${LEGACY_SCRIPTS[$legacy_file]}"
+              versioned_file="${pattern/\{version\}/$version}"
+              if ! echo "$MODIFIED_FILES" | grep -q "^${versioned_file}$"; then
                 ERRORS+="\n- Legacy script '${legacy_file}' was changed, but its counterpart '${versioned_file}' was not."
               fi
             done