cleanup deps 1/n (#4400)

Co-authored-by: sleepcoo <sleepcoo@gmail.com>

python/sglang/srt/layers/rotary_embedding.py

@@ -6,7 +6,6 @@ from typing import Any, Dict, List, Optional, Tuple, Union
 
 import torch
 import torch.nn as nn
-from vllm import _custom_ops as ops
 
 from sglang.srt.custom_op import CustomOp
 from sglang.srt.utils import is_cuda_available
@@ -14,6 +13,8 @@ from sglang.srt.utils import is_cuda_available
 _is_cuda_available = is_cuda_available()
 if _is_cuda_available:
     from sgl_kernel import apply_rope_with_cos_sin_cache_inplace
+else:
+    from vllm import _custom_ops as ops
 
 
 def _rotate_neox(x: torch.Tensor) -> torch.Tensor: