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/v1/engine/utils.py

@@ -3,7 +3,7 @@
 
 import random
 from dataclasses import dataclass
-from typing import Optional, Union
+from typing import TypeAlias
 
 import torch
 from transformers import PreTrainedTokenizer, PreTrainedTokenizerFast
@@ -12,7 +12,7 @@ from vllm.engine.arg_utils import EngineArgs
 from vllm.v1.engine import EngineCoreOutput, FinishReason
 from vllm.v1.outputs import LogprobsLists, LogprobsTensors
 
-GeneralTokenizerType = Union[PreTrainedTokenizer, PreTrainedTokenizerFast]
+GeneralTokenizerType: TypeAlias = PreTrainedTokenizer | PreTrainedTokenizerFast
 
 # Number of sample logprobs to request when testing sample logprobs
 NUM_SAMPLE_LOGPROBS_UNDER_TEST = 5
@@ -332,16 +332,15 @@ class MockEngineCore:
         # For each request, for each sampled token offset,
         # a tuple of
         # (list of topk token ids, list of sample logprob vals, rank)
-        generated_logprobs_raw: Optional[
-            list[list[tuple[list[int], list[float], int]]]
-        ] = None,
+        generated_logprobs_raw: list[list[tuple[list[int], list[float], int]]]
+        | None = None,
         # For each request, a tuple of
         # (prompt logprob val matrix, prompt logprob tok id matrix);
         # each matrix has dimensions
         # (num prompt toks) x (num prompt logprobs+1)
-        prompt_logprobs_raw: Optional[list[LogprobsTensors]] = None,
-        eos_token_id: Optional[int] = None,
-        stop_token_ids: Optional[list[int]] = None,
+        prompt_logprobs_raw: list[LogprobsTensors] | None = None,
+        eos_token_id: int | None = None,
+        stop_token_ids: list[int] | None = None,
         ignore_eos: bool = False,
     ) -> None:
         self.num_requests = len(tokens_list)