Update latest-staging workflow

Author: david-rocca

.github/workflows/latest-staging.yml

@@ -15,7 +15,7 @@ jobs:
     # needs: npm-run-tests
     steps:
     - name: Checkout Repository
-      uses: actions/checkout@v2
+      uses: actions/checkout@ee0669bd1cc54295c223e0bb666b733df41de1c5
     - name: Log in to GCR
       run: |
         docker login docker.pkg.github.com \