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

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

tools/check_init_lazy_imports.py

@@ -5,8 +5,6 @@ i.e: appears only within the ``if typing.TYPE_CHECKING:`` guard,
 **except** for a short whitelist.
 """
 
-from __future__ import annotations
-
 import ast
 import pathlib
 import sys

tools/enforce_regex_import.py

@@ -1,7 +1,5 @@
 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
-from __future__ import annotations
-
 import subprocess
 from pathlib import Path
 

tools/pre_commit/mypy.py

@@ -20,7 +20,6 @@ Args:
 
 import subprocess
 import sys
-from typing import Optional
 
 import regex as re
 
@@ -96,8 +95,8 @@ def group_files(changed_files: list[str]) -> dict[str, list[str]]:
 
 def mypy(
     targets: list[str],
-    python_version: Optional[str],
-    follow_imports: Optional[str],
+    python_version: str | None,
+    follow_imports: str | None,
     file_group: str,
 ) -> int:
     """

tools/profiler/visualize_layerwise_profile.py

@@ -7,7 +7,7 @@ import json
 import math
 import os
 from pathlib import Path
-from typing import Any, Optional
+from typing import Any
 
 import matplotlib.pyplot as plt
 import pandas as pd
@@ -373,7 +373,7 @@ def plot_trace_df(
     traces_df: pd.DataFrame,
     plot_metric: str,
     plot_title: str,
-    output: Optional[Path] = None,
+    output: Path | None = None,
 ):
     def get_phase_description(traces_df: pd.DataFrame, phase: str) -> str:
         phase_df = traces_df.query(f'phase == "{phase}"')