Add Slack notifications on failure (#620)

since we didn't notice failed release action for a whole week.
We don't add the notifications for failed PRs since it would spam our
Slack channel whenever someone opens a PR where tests are failing.

.github/workflows/publish-versioned-api-ref.yml

@@ -36,3 +36,10 @@ jobs:
           git add ./API_Reference_${{ steps.get_version.outputs.VERSION }}.asciidoc
           git add ./Wiki_Sidebar.md
           git commit -m "Publish version ${{ steps.get_version.outputs.VERSION }} API Reference" && git push
+      - uses: 8398a7/action-slack@v3
+        with:
+          status: ${{ job.status }}
+          fields: repo,message,action,eventName
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: failure()

.github/workflows/release.yml

@@ -14,3 +14,10 @@ jobs:
       uses: rajatjindal/[email protected]
       with:
         krew_template_file: hack/rabbitmq.yaml
+    - uses: 8398a7/action-slack@v3
+      with:
+        status: ${{ job.status }}
+        fields: repo,message,action,eventName
+      env:
+        SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+      if: failure()

.github/workflows/update-latest-api-ref.yml

@@ -28,3 +28,10 @@ jobs:
           cp ../cluster-operator/docs/api/rabbitmq.com.ref.asciidoc ./API_Reference.asciidoc
           git add ./API_Reference.asciidoc
           git diff-index --quiet HEAD || git commit -m "Update Latest API Reference" && git push
+      - uses: 8398a7/action-slack@v3
+        with:
+          status: ${{ job.status }}
+          fields: repo,message,action,eventName
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: failure()