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

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

examples/offline_inference/multilora_inference.py

@@ -7,8 +7,6 @@ for offline inference.
 Requires HuggingFace credentials for access to Llama2.
 """
 
-from typing import Optional
-
 from huggingface_hub import snapshot_download
 
 from vllm import EngineArgs, LLMEngine, RequestOutput, SamplingParams
@@ -17,7 +15,7 @@ from vllm.lora.request import LoRARequest
 
 def create_test_prompts(
     lora_path: str,
-) -> list[tuple[str, SamplingParams, Optional[LoRARequest]]]:
+) -> list[tuple[str, SamplingParams, LoRARequest | None]]:
     """Create a list of test prompts with their sampling parameters.
 
     2 requests for base model, 4 requests for the LoRA. We define 2
@@ -68,7 +66,7 @@ def create_test_prompts(
 
 def process_requests(
     engine: LLMEngine,
-    test_prompts: list[tuple[str, SamplingParams, Optional[LoRARequest]]],
+    test_prompts: list[tuple[str, SamplingParams, LoRARequest | None]],
 ):
     """Continuously process a list of prompts and handle the outputs."""
     request_id = 0