Update schedule for GPU tests (#159)

Author: welpaolo

.github/workflows/ci-gpu.yaml

@@ -10,7 +10,7 @@ concurrency:
 on:
   pull_request:
   schedule:
-    - cron: "53 0 * * *" # Daily at 00:53 UTC
+    - cron: "0 0 * * 0" # Weekly at 00:00 UTC on Sunday
 
 jobs:
   lint: