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/modular_kernel_tools/parallel_utils.py

@@ -3,11 +3,12 @@
 import dataclasses
 import os
 import traceback
-from typing import Any, Callable, Optional
+from collections.abc import Callable
+from typing import Any, Concatenate
 
 import torch
 from torch.multiprocessing import spawn  # pyright: ignore[reportPrivateImportUsage]
-from typing_extensions import Concatenate, ParamSpec
+from typing_extensions import ParamSpec
 
 from vllm.config import VllmConfig, set_current_vllm_config
 from vllm.distributed import init_distributed_environment, initialize_model_parallel
@@ -58,9 +59,9 @@ def _worker_parallel_launch(
     world_local_size: int,
     node_rank: int,
     init_method: str,
-    worker: Callable[Concatenate[ProcessGroupInfo, Optional[VllmConfig], Any, P], None],
-    vllm_config: Optional[VllmConfig],
-    env_dict: Optional[dict],
+    worker: Callable[Concatenate[ProcessGroupInfo, VllmConfig | None, Any, P], None],
+    vllm_config: VllmConfig | None,
+    env_dict: dict | None,
     *args: P.args,
     **kwargs: P.kwargs,
 ) -> None: