Bump rtCamp/action-slack-notify from 2.2.1 to 2.3.0

Bumps [rtCamp/action-slack-notify](https://github.com/rtcamp/action-slack-notify) from 2.2.1 to 2.3.0.
- [Release notes](https://github.com/rtcamp/action-slack-notify/releases)
- [Commits](rtCamp/action-slack-notify@b24d75f...4e5fb42)

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

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

.github/workflows/release.yaml

@@ -50,7 +50,7 @@ jobs:
           path: ./serving.yaml
 
       - name: Post failure notice to Slack
-        uses: rtCamp/action-slack-notify@b24d75fe0e728a4bf9fc42ee217caa686d141ee8 # v2.2.1
+        uses: rtCamp/action-slack-notify@4e5fb42d249be6a45a298f3c9543b111b02f7907 # v2.3.0
         if: ${{ failure() }}
         env:
           SLACK_ICON: http://github.com/chainguard-dev.png?size=48