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/attention/test_flashinfer.py

@@ -1,7 +1,6 @@
 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
-from typing import Optional
 
 import flashinfer
 import pytest
@@ -26,8 +25,8 @@ def ref_paged_attn(
     kv_lens: list[int],
     block_tables: torch.Tensor,
     scale: float,
-    sliding_window: Optional[int] = None,
-    soft_cap: Optional[float] = None,
+    sliding_window: int | None = None,
+    soft_cap: float | None = None,
 ) -> torch.Tensor:
     num_seqs = len(query_lens)
     block_tables = block_tables.cpu().numpy()
@@ -90,8 +89,8 @@ def test_flashinfer_decode_with_paged_kv(
     head_size: int,
     dtype: torch.dtype,
     block_size: int,
-    soft_cap: Optional[float],
-    sliding_window: Optional[int],
+    soft_cap: float | None,
+    sliding_window: int | None,
 ) -> None:
     torch.set_default_device("cuda")
     current_platform.seed_everything(0)
@@ -185,8 +184,8 @@ def test_flashinfer_prefill_with_paged_kv(
     head_size: int,
     dtype: torch.dtype,
     block_size: int,
-    soft_cap: Optional[float],
-    sliding_window: Optional[int],
+    soft_cap: float | None,
+    sliding_window: int | None,
 ) -> None:
     torch.set_default_device("cuda")
     current_platform.seed_everything(0)
@@ -288,7 +287,7 @@ def test_flashinfer_prefill_with_paged_fp8_kv(
     head_size: int,
     dtype: torch.dtype,
     block_size: int,
-    soft_cap: Optional[float],
+    soft_cap: float | None,
 ) -> None:
     pytest.skip("TODO: fix the accuracy issue")
     torch.set_default_device("cuda")
@@ -398,7 +397,7 @@ def test_flashinfer_decode_with_paged_fp8_kv(
     head_size: int,
     dtype: torch.dtype,
     block_size: int,
-    soft_cap: Optional[float],
+    soft_cap: float | None,
 ) -> None:
     # test doesn't work for num_heads = (16,16)
     torch.set_default_device("cuda")