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/models/multimodal/generation/test_qwen2_vl.py

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
-from typing import Any, Optional, TypedDict, Union
+from typing import Any, TypedDict
 
 import numpy.typing as npt
 import pytest
@@ -83,7 +83,7 @@ class Qwen2VLPromptVideoEmbeddingInput(TypedDict):
 
 
 def batch_make_image_embeddings(
-    image_batches: list[Union[Image.Image, list[Image.Image]]],
+    image_batches: list[Image.Image | list[Image.Image]],
     processor,
     llm: VllmRunner,
 ) -> list[Qwen2VLPromptImageEmbeddingInput]:
@@ -272,7 +272,7 @@ def run_embedding_input_test(
     num_logprobs: int,
     mm_limit: int,
     tensor_parallel_size: int,
-    distributed_executor_backend: Optional[str] = None,
+    distributed_executor_backend: str | None = None,
 ):
     """Inference result should be the same between
     original image/video input and image/video embeddings input.