Bump reviewdog/action-yamllint from 1.6.1 to 1.21.0

Bumps [reviewdog/action-yamllint](https://github.com/reviewdog/action-yamllint) from 1.6.1 to 1.21.0.
- [Release notes](https://github.com/reviewdog/action-yamllint/releases)
- [Commits](reviewdog/action-yamllint@v1.6.1...v1.21.0)

---
updated-dependencies:
- dependency-name: reviewdog/action-yamllint
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/reviewdog.yml

@@ -29,7 +29,7 @@ jobs:
     steps:
       - uses: actions/[email protected]
       - name: yamllint
-        uses: reviewdog/action-yamllint@v1.6.1
+        uses: reviewdog/action-yamllint@v1.21.0
         with:
           github_token: ${{ secrets.github_token }}
           reporter: github-check