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/kernels/quantization/test_cutlass_w4a8.py

@@ -6,7 +6,6 @@ Run `pytest tests/kernels/quantization/test_cutlass_w4a8.py`.
 """
 
 from dataclasses import dataclass
-from typing import Optional
 
 import pytest
 import torch
@@ -60,10 +59,10 @@ SCHEDULES = [
 class TypeConfig:
     act_type: torch.dtype
     weight_type: ScalarType
-    output_type: Optional[torch.dtype]
-    group_scale_type: Optional[torch.dtype]
-    channel_scale_type: Optional[torch.dtype]
-    token_scale_type: Optional[torch.dtype]
+    output_type: torch.dtype | None
+    group_scale_type: torch.dtype | None
+    channel_scale_type: torch.dtype | None
+    token_scale_type: torch.dtype | None
 
 
 @dataclass
@@ -80,7 +79,7 @@ class Tensors:
 # (Act Type, Weight Type, Output Type, Scale Type, ZeroPoints,
 #  Ch Scales Type, Tok Scales Type)
 TestTypeTuple = tuple[
-    list[torch.dtype], ScalarType, Optional[torch.dtype], Optional[torch.dtype], bool
+    list[torch.dtype], ScalarType, torch.dtype | None, torch.dtype | None, bool
 ]
 TEST_TYPES = [
     *(
@@ -116,8 +115,8 @@ def cutlass_quantize_and_pack(
     atype: torch.dtype,
     w: torch.Tensor,
     wtype: ScalarType,
-    stype: Optional[torch.dtype],
-    group_size: Optional[int],
+    stype: torch.dtype | None,
+    group_size: int | None,
     zero_points: bool = False,
 ):
     assert wtype.is_integer(), "TODO: support floating point weights"
@@ -143,7 +142,7 @@ def cutlass_quantize_and_pack(
 
 
 def create_test_tensors(
-    shape: tuple[int, int, int], types: TypeConfig, group_size: Optional[int]
+    shape: tuple[int, int, int], types: TypeConfig, group_size: int | None
 ) -> Tensors:
     m, n, k = shape
 
@@ -185,8 +184,8 @@ def create_test_tensors(
 def mm_test_helper(
     types: TypeConfig,
     tensors: Tensors,
-    group_size: Optional[int] = None,
-    schedule: Optional[str] = None,
+    group_size: int | None = None,
+    schedule: str | None = None,
 ):
     # CUTLASS upstream uses fp8 with fastaccum as reference
     # https://github.com/NVIDIA/cutlass/blob/main/examples/55_hopper_mixed_dtype_gemm/55_hopper_int4_fp8_gemm.cu#L406