Bump slackapi/slack-github-action from 1.27.0 to 2.1.0

Bumps [slackapi/slack-github-action](https://github.com/slackapi/slack-github-action) from 1.27.0 to 2.1.0.
- [Release notes](https://github.com/slackapi/slack-github-action/releases)
- [Commits](slackapi/slack-github-action@v1.27.0...v2.1.0)

---
updated-dependencies:
- dependency-name: slackapi/slack-github-action
  dependency-version: 2.1.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/moby-latest.yml

@@ -43,7 +43,7 @@ jobs:
       - name: Notify to Slack on failures
         if: failure()
         id: slack
-        uses: slackapi/slack-github-action@v1.27.0
+        uses: slackapi/slack-github-action@v2.1.0
         with:
           payload: |
             {