Cover Cron unschedule event error for hook: saas related errors when check that no wpr related error

[Mai-Saad]

Related test case https://wpmediaqa.testrail.io/index.php?/cases/view/20907
Related Github: wp-media/wp-rocket#7797

Currently: we check debug.log for any wp-rocket related errors and display notice
Required: display notice as well if there is this entry in debug.log Cron unschedule event error for hook: rocket

[Mai-Saad]

Note: it will need PR at e2e as well to go through the scenario that may trigger the error