Bump slackapi/slack-github-action from 1.25.0 to 1.26.0 (#25297)

Bumps [slackapi/slack-github-action](https://github.com/slackapi/slack-github-action) from 1.25.0 to 1.26.0.
- [Release notes](https://github.com/slackapi/slack-github-action/releases)
- [Commits](6c661ce588...70cd7be8e4)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/cd-pipeline.yml

@@ -154,7 +154,7 @@ jobs:
     steps:
       - name: Notify in Slack channel
         if: ${{ needs.update-index.result != 'success' }}
-        uses: slackapi/slack-github-action@6c661ce58804a1a20f6dc5fbee7f0381b469e001
+        uses: slackapi/slack-github-action@70cd7be8e40a46e8b0eced40b0de447bdb42f68e
         with:
           channel-id: ${{ secrets.CD_SLACK_CHANNEL_ID }}
           payload: |