Update deploy-preview.yml

Author: sserrata

.github/workflows/deploy-preview.yml

@@ -144,10 +144,9 @@ jobs:
           node-version: "20"
           cache: "yarn"
 
-      # 2. ADDED AUTHENTICATION STEP
       - name: Authenticate to Google Cloud
         id: auth
-        uses: google-github-actions/auth@v2
+        uses: google-github-actions/auth@b7593ed2efd1c1617e1b0254da33b86225adb2a5
         with:
           workload_identity_provider: ${{ secrets.WIF_PROVIDER }}
           service_account: ${{ secrets.WIF_SERVICE_ACCOUNT }}