Give check-version job pull request write permissions (#8743)

* Add pull_request write permissions

* fix typo

Author: dlarocque

.github/workflows/check-vertexai-responses.yml

@@ -22,6 +22,7 @@ jobs:
     # Allow GITHUB_TOKEN to have write permissions
     permissions:
       contents: write
+      pull-requests: write
     steps:
       - uses: actions/checkout@v4
       - name: Clone mock responses