chore(deps): bump kentaro-m/auto-assign-action

Bumps [kentaro-m/auto-assign-action](https://github.com/kentaro-m/auto-assign-action) from 2540405c417e3376a45f5fc809acd86fe2dfeec5 to 646e8b333af1f2578621db2ad3a1373665e53201.
- [Release notes](https://github.com/kentaro-m/auto-assign-action/releases)
- [Commits](kentaro-m/auto-assign-action@2540405...646e8b3)

---
updated-dependencies:
- dependency-name: kentaro-m/auto-assign-action
  dependency-version: 646e8b333af1f2578621db2ad3a1373665e53201
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/auto-assign.yml

@@ -11,4 +11,4 @@ jobs:
   add-assignee:
     runs-on: ubuntu-latest
     steps:
-      - uses: kentaro-m/auto-assign-action@2540405c417e3376a45f5fc809acd86fe2dfeec5
+      - uses: kentaro-m/auto-assign-action@646e8b333af1f2578621db2ad3a1373665e53201