Clean up server_args.py to have a dedicated function for model specific adjustments (#8983)

python/sglang/srt/layers/quantization/__init__.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 
 import builtins
 import inspect
-from typing import TYPE_CHECKING, Callable, Dict, Optional, Type, Union
+from typing import TYPE_CHECKING, Dict, Optional, Type
 
 import torch