Update Optional[x] -> x | None and Union[x, y] to x | y (#26633)

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

vllm/model_executor/layers/mamba/short_conv.py

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
-from typing import TYPE_CHECKING, Optional
+from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
     from vllm.attention.backends.abstract import AttentionBackend
@@ -38,8 +38,8 @@ class ShortConv(MambaBase, CustomOp):
         config,
         dim: int,
         layer_idx: int,
-        model_config: Optional[ModelConfig] = None,
-        cache_config: Optional[CacheConfig] = None,
+        model_config: ModelConfig | None = None,
+        cache_config: CacheConfig | None = None,
         prefix: str = "",
     ):
         super().__init__()