Added docker system prune for CI.

Author: pantierra

.github/workflows/ci.yml

@@ -78,8 +78,11 @@ jobs:
       - name: Cleanup
         if: always()
         run: |
+          echo "=== Cleaning up Helm release and namespace ==="
           helm uninstall "$RELEASE_NAME" -n eoapi || true
           kubectl delete namespace eoapi || true
+          echo "=== Cleaning up Docker resources ==="
+          docker system prune -af --volumes || true
 
   validate-docs:
     name: Validate documentation