Add Registry Garbage Collection schedule job

To test the Registry v3 garbage collection in preprod, a new job needs to be created to ensure this runs as a schedule and only when $REGISTRY_GC_ONLY is set to true, filtering and running only the tests in qa/specs/features/browser_ui/5_package with --tag registry_gc

The reasoning to separate this from the normal deployment path is mainly the time dependency. More info on Test online garbage collection on pre-prod