chore: enable F821, F401, W293 (#9503)

* auto fixes

* auto fix pt2 and transitive deps and undefined var checking locals()

* manual fixes (ignored or letta-code fixed)

* fix circular import

.github/scripts/model-sweep/model_sweep.py

@@ -1,16 +1,12 @@
 import base64
 import json
 import os
-import socket
-import threading
 import time
 import uuid
 from typing import Any, Dict, List
 
 import httpx
 import pytest
-import requests
-from dotenv import load_dotenv
 from letta_client import Letta, MessageCreate, Run
 from letta_client.core.api_error import ApiError
 from letta_client.types import (