fix: Replace remaining deprecated typing imports with built-in types

- Replace List[...] with list[...] in crew.py method signatures
- Replace Dict[str, Any] with dict[str, Any] in crew.py and task.py
- Fix all undefined name errors from deprecated typing imports
- Maintain backward compatibility while modernizing type hints

Co-Authored-By: João <joao@crewai.com>

src/crewai/agents/agent_builder/base_agent.py

@@ -2,7 +2,7 @@ import uuid
 from abc import ABC, abstractmethod
 from copy import copy as shallow_copy
 from hashlib import md5
-from typing import Any, Callable, Dict, List, Optional, TypeVar
+from typing import Any, Callable, Optional, TypeVar
 
 from pydantic import (
     UUID4,