Fix permissions for git-auto-commit-action (nginx#2705)

Author: miledxz

.github/workflows/ci.yml

@@ -33,6 +33,8 @@ jobs:
       min_k8s_version: ${{ steps.vars.outputs.min_k8s_version }}
       k8s_latest: ${{ steps.vars.outputs.k8s_latest }}
       helm_changes: ${{ steps.filter.outputs.charts }}
+    permissions:
+      contents: write
     steps:
       - name: Checkout Repository
         uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871 # v4.2.1