Bumps [slackapi/slack-github-action](https://github.com/slackapi/slack-github-action) from 1.18.0 to 1.19.0.
- [Release notes](https://github.com/slackapi/slack-github-action/releases)
- [Commits](https://github.com/slackapi/slack-github-action/compare/v1.18.0...v1.19.0

)

---
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>