Awx: unauthenticated debug endpoints trigger scheduler operations

A flaw was found in AWX. The debug API endpoints (/api/debug/task_manager/, /api/debug/dependency_manager/, /api/debug/workflow_manager/) are registered unconditionally in the URL configuration and use AllowAny permission class with _ignore_model_permissions=True. This allows an unauthenticated remote attacker to repeatedly invoke scheduler operations that acquire database advisory locks and open transactions, potentially leading to resource exhaustion and degraded service availability.