Bump slackapi/slack-github-action in /.github/workflows

Bumps [slackapi/slack-github-action](https://github.com/slackapi/slack-github-action) from 1.26.0 to 1.27.0.
- [Release notes](https://github.com/slackapi/slack-github-action/releases)
- [Commits](slackapi/slack-github-action@v1.26.0...v1.27.0)

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

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

.github/workflows/ci-testing.yml

@@ -115,7 +115,7 @@ jobs:
     steps:
       - name: Check for failure and notify
         if: (needs.Tests.result == 'failure' || needs.Tests.result == 'cancelled') && github.repository == 'ultralytics/yolov3' && (github.event_name == 'schedule' || github.event_name == 'push')
-        uses: slackapi/slack-github-action@v1.26.0
+        uses: slackapi/slack-github-action@v1.27.0
         with:
           payload: |
             {"text": "<!channel> GitHub Actions error for ${{ github.workflow }} ❌\n\n\n*Repository:* https://github.com/${{ github.repository }}\n*Action:* https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}\n*Author:* ${{ github.actor }}\n*Event:* ${{ github.event_name }}\n"}