Revert removing the unused imports (#385)

python/sglang/srt/models/yivl.py

@@ -1,6 +1,7 @@
 """Inference-only Yi-VL model."""
 
-from typing import Optional
+import os
+from typing import List, Optional
 
 import torch
 import torch.nn as nn
@@ -12,6 +13,7 @@ from vllm.model_executor.weight_utils import (
 
 from sglang.srt.models.llava import (
     LlavaLlamaForCausalLM,
+    clip_vision_embed_forward,
     monkey_path_clip_vision_embed_forward,
 )