maint(deps): bump slackapi/slack-github-action from 1.27.0 to 2.0.0

Bumps [slackapi/slack-github-action](https://github.com/slackapi/slack-github-action) from 1.27.0 to 2.0.0.
- [Release notes](https://github.com/slackapi/slack-github-action/releases)
- [Commits](slackapi/slack-github-action@v1.27.0...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/ci.yaml

@@ -99,7 +99,7 @@ jobs:
       - name: Notify if scheduled run fails
         id: slack-notify
         if: ${{ failure() && github.event_name == 'schedule' }}
-        uses: slackapi/slack-github-action@v1.27.0
+        uses: slackapi/slack-github-action@v2.0.0
         with:
           payload: |
             {
@@ -204,7 +204,7 @@ jobs:
       - name: Notify if scheduled run fails
         id: slack-notify
         if: ${{ failure() && github.event_name == 'schedule' }}
-        uses: slackapi/slack-github-action@v1.27.0
+        uses: slackapi/slack-github-action@v2.0.0
         with:
           payload: |
             {