[Lint] Add python/sglang to ruff F401 checks and remove unused imports in files (#11685)

python/sglang/srt/metrics/func_timer.py

@@ -18,7 +18,7 @@ Records the latency of some functions
 import asyncio
 import time
 from functools import wraps
-from typing import Any, Callable, List, Optional
+from typing import Any, Callable, Optional
 
 from sglang.srt.metrics.utils import exponential_buckets