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_phi4_multimodal.py

@@ -3,7 +3,6 @@
 
 import os
 from collections.abc import Sequence
-from typing import Optional
 
 import librosa
 import pytest
@@ -57,7 +56,7 @@ if current_platform.is_rocm():
 def run_test(
     hf_runner: type[HfRunner],
     vllm_runner: type[VllmRunner],
-    inputs: Sequence[tuple[list[str], PromptImageInput, Optional[PromptAudioInput]]],
+    inputs: Sequence[tuple[list[str], PromptImageInput, PromptAudioInput | None]],
     model: str,
     *,
     max_model_len: int,
@@ -66,7 +65,7 @@ def run_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 hf and vllm.