build(deps): bump slackapi/slack-github-action from 2.1.0 to 2.1.1

Bumps [slackapi/slack-github-action](https://github.com/slackapi/slack-github-action) from 2.1.0 to 2.1.1.
- [Release notes](https://github.com/slackapi/slack-github-action/releases)
- [Commits](slackapi/slack-github-action@v2.1.0...v2.1.1)

---
updated-dependencies:
- dependency-name: slackapi/slack-github-action
  dependency-version: 2.1.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/ci-nightly.yml

@@ -79,7 +79,7 @@ jobs:
 
       - name: Post a message in slack channel if failing
         if: ${{ failure() }}
-        uses: slackapi/[email protected].0
+        uses: slackapi/[email protected].1
         with:
           webhook: ${{ secrets.SLACK_WEBHOOK_URL }}
           webhook-type: incoming-webhook