Bump kentaro-m/auto-assign-action from 1.2.3 to 1.2.4

Bumps [kentaro-m/auto-assign-action](https://github.com/kentaro-m/auto-assign-action) from 1.2.3 to 1.2.4.
- [Release notes](https://github.com/kentaro-m/auto-assign-action/releases)
- [Commits](kentaro-m/auto-assign-action@v1.2.3...v1.2.4)

---
updated-dependencies:
- dependency-name: kentaro-m/auto-assign-action
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

.github/workflows/assign-pr.yml

@@ -6,6 +6,6 @@ jobs:
   add-reviews:
     runs-on: ubuntu-latest
     steps:
-      - uses: kentaro-m/[email protected].3
+      - uses: kentaro-m/[email protected].4
         with:
           repo-token: "${{ secrets.GITHUB_TOKEN }}"