Bump slackapi/slack-github-action from 1.26.0 to 2.0.0

Bumps [slackapi/slack-github-action](https://github.com/slackapi/slack-github-action) from 1.26.0 to 2.0.0.
- [Release notes](https://github.com/slackapi/slack-github-action/releases)
- [Commits](slackapi/slack-github-action@v1.26...v2.0.0)

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

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

.github/workflows/test-vizro-ai-ui.yml

@@ -56,7 +56,7 @@ jobs:
 
       - name: Send custom JSON data to Slack
         id: slack
-        uses: slackapi/slack-github-action@v1.26.0
+        uses: slackapi/slack-github-action@v2.0.0
         if: failure()
         with:
           payload: |