[Misc] Replace Optional[X] with X | None syntax (#33332)

Signed-off-by: carlory <baofa.fan@daocloud.io>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

vllm/model_executor/layers/quantization/inc.py

@@ -2,7 +2,7 @@
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 from fractions import Fraction
-from typing import TYPE_CHECKING, Any, Optional
+from typing import TYPE_CHECKING, Any
 
 import regex as re
 import torch
@@ -456,7 +456,7 @@ class INCConfig(QuantizationConfig):
     @classmethod
     def override_quantization_method(
         cls, hf_quant_cfg, user_quant
-    ) -> Optional["QuantizationMethods"]:
+    ) -> "QuantizationMethods | None":
         """Override the `auto-round` method to `inc`."""
         is_auto_round_format = hf_quant_cfg.get("quant_method", None) == "auto-round"
         if is_auto_round_format: