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/tokenization/test_tokenizer_registry.py

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
-from typing import TYPE_CHECKING, Any, Optional, Union
+from typing import TYPE_CHECKING, Any
 
 from vllm.transformers_utils.tokenizer import get_tokenizer
 from vllm.transformers_utils.tokenizer_base import TokenizerBase, TokenizerRegistry
@@ -61,11 +61,11 @@ class TestTokenizer(TokenizerBase):
 
     def __call__(
         self,
-        text: Union[str, list[str], list[int]],
-        text_pair: Optional[str] = None,
+        text: str | list[str] | list[int],
+        text_pair: str | None = None,
         add_special_tokens: bool = False,
         truncation: bool = False,
-        max_length: Optional[int] = None,
+        max_length: int | None = None,
     ):
         raise NotImplementedError()
 
@@ -79,17 +79,17 @@ class TestTokenizer(TokenizerBase):
         self,
         text: str,
         truncation: bool = False,
-        max_length: Optional[int] = None,
+        max_length: int | None = None,
     ) -> list[int]:
         raise NotImplementedError()
 
-    def encode(self, text: str, add_special_tokens: Optional[bool] = None) -> list[int]:
+    def encode(self, text: str, add_special_tokens: bool | None = None) -> list[int]:
         raise NotImplementedError()
 
     def apply_chat_template(
         self,
         messages: list["ChatCompletionMessageParam"],
-        tools: Optional[list[dict[str, Any]]] = None,
+        tools: list[dict[str, Any]] | None = None,
         **kwargs,
     ) -> list[int]:
         raise NotImplementedError()
@@ -97,9 +97,7 @@ class TestTokenizer(TokenizerBase):
     def convert_tokens_to_string(self, tokens: list[str]) -> str:
         raise NotImplementedError()
 
-    def decode(
-        self, ids: Union[list[int], int], skip_special_tokens: bool = True
-    ) -> str:
+    def decode(self, ids: list[int] | int, skip_special_tokens: bool = True) -> str:
         raise NotImplementedError()
 
     def convert_ids_to_tokens(