github-action: bump slackapi/slack-github-action from 1.25.0 to 2.0.0

Bumps [slackapi/slack-github-action](https://github.com/slackapi/slack-github-action) from 1.25.0 to 2.0.0.
- [Release notes](https://github.com/slackapi/slack-github-action/releases)
- [Commits](slackapi/slack-github-action@6c661ce...485a9d4)

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

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/deploy.yml

@@ -68,7 +68,7 @@ jobs:
 
       - name: Slack notify on failure
         if: failure()
-        uses: slackapi/slack-github-action@6c661ce58804a1a20f6dc5fbee7f0381b469e001
+        uses: slackapi/slack-github-action@485a9d42d3a73031f12ec201c457e2162c45d02d
         with:
           payload: |
             {