feat: Add permissions

Author: lamATnginx

.github/workflows/build-push.yml

@@ -77,6 +77,7 @@ jobs:
     if: github.event_name == 'repository_dispatch'
     needs: call-docs-build-push
     runs-on: ubuntu-latest
+    permissions: read-all
     steps:
       - name: Trigger 'Slack notification for new theme release' workflow in 'nginx-hugo-theme' repo.
         run: |