build(deps): bump 8398a7/action-slack

Bumps [8398a7/action-slack](https://github.com/8398a7/action-slack) from 44a35a96508f31f916f99ad5b68f489ae45659a2 to 3.8.3. This release includes the previously tagged commit.
- [Release notes](https://github.com/8398a7/action-slack/releases)
- [Commits](8398a7/action-slack@44a35a9...fac0d8d)

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

.github/workflows/ci.yml

@@ -36,7 +36,7 @@ jobs:
         name: Report code coverage
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
-      - uses: 8398a7/action-slack@44a35a96508f31f916f99ad5b68f489ae45659a2
+      - uses: 8398a7/action-slack@fac0d8dcd9eec18c79dae8addc99aab092c4cc50
         name: Notify on Slack
         if: ${{ failure() }}
         with: