Add Java caching CI job (2)

Author: jbachorik

.github/workflows/cache_java.yml

@@ -27,6 +27,7 @@ jobs:
   cache-amd64:
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v3
       - name: Setup OS
         run: |
           sudo apt-get update -y