fix ruff

src/chat/utils/statistic.py

@@ -1,8 +1,5 @@
 import asyncio
 import concurrent.futures
-import json
-import os
-import glob
 
 from collections import defaultdict
 from datetime import datetime, timedelta

src/chat/utils/utils_image.py

@@ -6,7 +6,6 @@ import uuid
 import io
 import asyncio
 import numpy as np
-import jieba
 
 from typing import Optional, Tuple
 from PIL import Image