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/distributed/test_comm_ops.py

@@ -5,9 +5,8 @@
 Run `pytest tests/distributed/test_comm_ops.py`.
 """
 
-from __future__ import annotations
-
-from typing import Any, Callable
+from collections.abc import Callable
+from typing import Any
 
 import pytest
 import ray