Warn users who want to be warned about failing comment workflows (#6758)

Author: DanielNoord

.github/workflows/primer_comment.yaml

@@ -138,3 +138,10 @@ jobs:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           leave_visible: 1
           issue_number: ${{ steps.post-comment.outputs.result }}
+      - name: Warn about failure
+        if: ${{ failure() }}
+        run: |
+          echo "🤖 **Comment workflow failed**. 🤖" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "Please investigate:" >> $GITHUB_STEP_SUMMARY
+          echo "@DanielNoord" >> $GITHUB_STEP_SUMMARY