Bump kentaro-m/auto-assign-action from 1.2.6 to 2.0.0

Bumps [kentaro-m/auto-assign-action](https://github.com/kentaro-m/auto-assign-action) from 1.2.6 to 2.0.0.
- [Release notes](https://github.com/kentaro-m/auto-assign-action/releases)
- [Commits](kentaro-m/auto-assign-action@v1.2.6...v2.0.0)

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

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

.github/workflows/assign-pr.yml

@@ -7,6 +7,6 @@ jobs:
     name: 'Auto Assign PR'
     runs-on: ubuntu-latest
     steps:
-      - uses: kentaro-m/auto-assign-action@v1.2.6
+      - uses: kentaro-m/auto-assign-action@v2.0.0
         with:
           repo-token: "${{ secrets.GITHUB_TOKEN }}"