chore: Change GPU integ test schedule to 3h interval (10pm/1am/4am PST) and timeout to 3h (aws#5945)

Author: lucasjia-aws

.github/workflows/gpu-integ-tests.yml

@@ -1,11 +1,11 @@
 name: GPU Integ Tests
 on:
   schedule:
-    # US Pacific (PST, UTC-8): 12:00 AM / 2:00 AM / 4:00 AM -> 08/10/12 UTC.
+    # US Pacific (PST, UTC-8): 10:00 PM / 1:00 AM / 4:00 AM -> 06/09/12 UTC.
     # All three fire within the same UTC day so the run-level CloudWatch metric
     # (GpuIntegRunFailure) aggregates correctly per day.
-    - cron: "0 8 * * *"
-    - cron: "0 10 * * *"
+    - cron: "0 6 * * *"
+    - cron: "0 9 * * *"
     - cron: "0 12 * * *"
   workflow_dispatch: