ci(github-actions): improve concurrency grouping with PR number fallback (#4101)

# Description of Changes

- Updated the `concurrency.group` key in the following GitHub Actions
workflows:
  - `.github/workflows/build.yml`
  - `.github/workflows/check_properties.yml`
  - `.github/workflows/sonarqube.yml`
- The grouping string now uses `github.event.pull_request.number` (if
present) as a fallback before falling back to `ref_name` or `ref`.
- This helps ensure better grouping for PR-based workflows, improving
job cancellation behavior and avoiding unnecessary parallel job
execution when multiple pushes occur on the same PR.

No functional behavior is changed in the actual build or check logic.

---

## Checklist

### General

- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [x] I have performed a self-review of my own code
- [x] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

.github/workflows/build.yml

@@ -16,7 +16,7 @@ on:
 # This ensures that jobs are grouped by the workflow and branch, allowing for cancellation of
 # in-progress jobs when a new commit is pushed to the same branch or a new pull request is opened.
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.ref_name || github.ref }}
+  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.ref_name || github.ref }}
   cancel-in-progress: true
 
 permissions:
@@ -147,7 +147,7 @@ jobs:
 
       - name: Generate OpenAPI documentation
         run: ./gradlew :stirling-pdf:generateOpenApiDocs
-      
+
       - name: Upload OpenAPI Documentation
         uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
         with:

.github/workflows/check_properties.yml

@@ -15,7 +15,7 @@ on:
 # This ensures that jobs are grouped by the workflow and branch, allowing for cancellation of
 # in-progress jobs when a new commit is pushed to the same branch or a new pull request is opened.
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.ref_name || github.ref }}
+  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.ref_name || github.ref }}
   cancel-in-progress: true
 
 permissions:
@@ -127,7 +127,7 @@ jobs:
 
             // Filter for relevant files based on the PR changes
             const changedFiles = files
-              .filter(file => 
+              .filter(file =>
                 file.status !== "removed" &&
                 /^app\/core\/src\/main\/resources\/messages_[a-zA-Z_]{2}_[a-zA-Z_]{2,7}\.properties$/.test(file.filename)
               )
@@ -289,4 +289,4 @@ jobs:
           rm -rf pr-branch
           rm -f pr-branch-messages_en_GB.properties main-branch-messages_en_GB.properties changed_files.txt result.txt
           echo "Cleanup complete."
-        continue-on-error: true # Ensure cleanup runs even if previous steps fail
+        continue-on-error: true # Ensure cleanup runs even if previous steps fail

.github/workflows/sonarqube.yml

@@ -18,7 +18,7 @@ on:
 # This ensures that jobs are grouped by the workflow and branch, allowing for cancellation of
 # in-progress jobs when a new commit is pushed to the same branch or a new pull request is opened.
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.ref_name || github.ref }}
+  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.ref_name || github.ref }}
   cancel-in-progress: true
 
 permissions: