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

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

tests/kernels/moe/parallel_utils.py

@@ -7,12 +7,13 @@ DeepEP test utilities
 import dataclasses
 import os
 import traceback
-from typing import Callable, Optional
+from collections.abc import Callable
+from typing import Concatenate
 
 import torch
 from torch.distributed import ProcessGroup
 from torch.multiprocessing import spawn  # pyright: ignore[reportPrivateImportUsage]
-from typing_extensions import Concatenate, ParamSpec
+from typing_extensions import ParamSpec
 
 from vllm.utils import get_open_port, has_deep_ep
 
@@ -126,8 +127,8 @@ def make_deepep_ht_a2a(
     pgi: ProcessGroupInfo,
     dp_size: int,
     ht_args: DeepEPHTArgs,
-    q_dtype: Optional[torch.dtype] = None,
-    block_shape: Optional[list[int]] = None,
+    q_dtype: torch.dtype | None = None,
+    block_shape: list[int] | None = None,
 ):
     import deep_ep
 
@@ -153,8 +154,8 @@ def make_deepep_ll_a2a(
     pg: ProcessGroup,
     pgi: ProcessGroupInfo,
     deepep_ll_args: DeepEPLLArgs,
-    q_dtype: Optional[torch.dtype] = None,
-    block_shape: Optional[list[int]] = None,
+    q_dtype: torch.dtype | None = None,
+    block_shape: list[int] | None = None,
 ):
     import deep_ep
 
@@ -185,10 +186,10 @@ def make_deepep_a2a(
     pg: ProcessGroup,
     pgi: ProcessGroupInfo,
     dp_size: int,
-    deepep_ht_args: Optional[DeepEPHTArgs],
-    deepep_ll_args: Optional[DeepEPLLArgs],
-    q_dtype: Optional[torch.dtype] = None,
-    block_shape: Optional[list[int]] = None,
+    deepep_ht_args: DeepEPHTArgs | None,
+    deepep_ll_args: DeepEPLLArgs | None,
+    q_dtype: torch.dtype | None = None,
+    block_shape: list[int] | None = None,
 ):
     if deepep_ht_args is not None:
         assert deepep_ll_args is None