Fix coverage comment from forks (cfug#2193)

When the coverage_comment workflow is triggered from a PR that
originates from a fork, then the workflow event does not contain the PR
number. But we need the PR number to attach the sticky coverage comment.
So workaround this by storing the PR number in the workflow artifact
that also contains the coverage result.

.github/workflows/coverage_comment.yml

@@ -22,10 +22,16 @@ jobs:
           workflow: tests.yml
           workflow_conclusion: success
           run_id: ${{ github.event.workflow_run.id }}
-          name: code-coverage-results.md
+          name: code-coverage-results
+      - name: Determine PR number
+        id: pr-number
+        run: |
+          PR_NUMBER=$(cat pr_number.txt)
+          echo "Found PR:$PR_NUMBER"
+          echo "value=$PR_NUMBER" >> $GITHUB_OUTPUT
       - name: Add PR comment
         uses: marocchino/sticky-pull-request-comment@v2
         with:
-          number: ${{ github.event.workflow_run.pull_requests[0].number }}
+          number: ${{ steps.pr-number.outputs.value }}
           recreate: true
           path: code-coverage-results.md

.github/workflows/tests.yml

@@ -103,9 +103,14 @@ jobs:
         with:
           artifact_download_workflow_names: 'Verify packages abilities,coverage_baseline'
           filename: 'coverage/cobertura.xml'
+      - name: '[Coverage] Write PR number to file'
+        if: ${{ matrix.sdk == 'stable' && github.actor != 'dependabot[bot]'}}
+        run: echo ${{ github.event.number }} > pr_number.txt
       - name: '[Coverage] Upload'
         if: ${{ matrix.sdk == 'stable' && github.actor != 'dependabot[bot]'}}
         uses: actions/upload-artifact@v4
         with:
-          name: code-coverage-results.md
-          path: code-coverage-results.md
+          name: code-coverage-results
+          path: |
+            code-coverage-results.md
+            pr_number.txt