APM-3869 Update cron schedule to run every 4th hour

Author: acarriedev

azure/cleanup-ecs-pr-proxies.yml

@@ -4,7 +4,7 @@ trigger: none
 pr: none
 
 schedules:
-  - cron: "0 2 * * *"
+  - cron: "0 */4 * * *" # Every 4 hours
     displayName: Daily PR cleanup
     branches:
       include: