refactor(autonomous_engine): remove unused lru_cache import from functools dependencies

The commit removes the now-unused `lru_cache` decorator import from `functools` in `autonomous_engine.py`. This cleanup eliminates dead code and reduces import overhead. The import was previously required for performance optimization but is no longer necessary after module refactoring. This change maintains cleaner dependencies and improves code maintainability.

autonomous_engine.py

@@ -12,7 +12,7 @@ from typing import Dict, List, Any, Optional, Tuple, Set, Union
 from datetime import datetime, timedelta
 from dataclasses import dataclass, asdict, field
 from enum import Enum
-from functools import lru_cache, wraps
+from functools import wraps
 from collections import defaultdict, deque
 import contextlib
 from contextlib import asynccontextmanager