Remove unused import from alerts route

The import for `RulesEngine` in `alerts.py` was unused and has been removed to clean up the code. This helps maintain clarity and avoids unnecessary dependencies.

keep/api/routes/alerts.py

@@ -49,7 +49,6 @@
 from keep.identitymanager.authenticatedentity import AuthenticatedEntity
 from keep.identitymanager.identitymanagerfactory import IdentityManagerFactory
 from keep.providers.providers_factory import ProvidersFactory
-from keep.rulesengine.rulesengine import RulesEngine
 from keep.searchengine.searchengine import SearchEngine
 from keep.workflowmanager.workflowmanager import WorkflowManager