chore(ci): fix permission for update_librarian_googleapis workflow

Author: zhumin8

.github/workflows/update_librarian_googleapis.yaml

@@ -33,6 +33,7 @@ jobs:
         repository: googleapis/google-cloud-java
         path: google-cloud-java
         fetch-depth: 0
+        token: ${{ secrets.CLOUD_JAVA_BOT_GITHUB_TOKEN }}
     - name: Check for Open PR
       env:
         GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}