re-enable workflow

Author: Dongxu-H

.github/workflows/gems-test-on-hopper.yaml

@@ -3,7 +3,7 @@ name: flag-gems-test-on-hopper
 on:
   push:
     branches: [ "master" ]
-    paths:
+    paths: 
       - '**.py'
       - '**.cpp'
       - '**.cu'