Bump 8398a7/action-slack from 3.15.1 to 3.16.2

Bumps [8398a7/action-slack](https://github.com/8398a7/action-slack) from 3.15.1 to 3.16.2.
- [Release notes](https://github.com/8398a7/action-slack/releases)
- [Commits](8398a7/action-slack@v3.15.1...v3.16.2)

---
updated-dependencies:
- dependency-name: 8398a7/action-slack
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

.github/workflows/test.yml

@@ -79,7 +79,7 @@ jobs:
     # notify developers if the scheduled check fails
     - name: Slack notification
       if: ${{ github.event_name == 'schedule' && (failure() || cancelled()) }}
-      uses: 8398a7/action-slack@v3.15.1
+      uses: 8398a7/action-slack@v3.16.2
       with:
         status: ${{ job.status }}
         fields: workflow,job,message,commit