Fix up build.yaml, once more

.github/workflows/build.yaml

@@ -5,6 +5,8 @@ on:
     branches: [main]
   pull_request:
     branches: [main]
+  workflow_dispatch:
+    branches: [stage0verify]
 
 # See https://docs.github.com/en/actions/learn-github-actions/workflow-syntax-for-github-actions#example-using-concurrency-to-cancel-any-in-progress-job-or-run
 concurrency:
@@ -41,10 +43,10 @@ jobs:
 
     steps:
       # Needed for GCS upload.
-      - name: Authenticate to Google Cloud
-        uses: google-github-actions/auth@v2
-        with:
-          credentials_json: ${{ secrets.GCP_SERVICE_ACCOUNT_KEY_JSON }}
+      # - name: Authenticate to Google Cloud
+      #   uses: google-github-actions/auth@v2
+      #   with:
+      #     credentials_json: ${{ secrets.GCP_SERVICE_ACCOUNT_KEY_JSON }}
 
       # Needed for GCS upload.
       - name: Setup Google Cloud