PEP 604: Remove some more uses of Union/Optional (#7515)

The following patterns still break mypy:

1. `type[]` at top level fails
2. `tuple[T1, T2]` at top level fails (but `tuple[T1, ...]` is fine)
3. `T1 | Callable[..., T2 | T3]` fails, but only <=3.9

This PR cleans up usage of `Union` and `Optional` outside these patterns.

stdlib/asyncio/trsock.pyi

@@ -2,10 +2,10 @@ import socket
 import sys
 from builtins import type as Type  # alias to avoid name clashes with property named "type"
 from types import TracebackType
-from typing import Any, BinaryIO, Iterable, NoReturn, Union, overload
+from typing import Any, BinaryIO, Iterable, NoReturn, overload
 
 # These are based in socket, maybe move them out into _typeshed.pyi or such
-_Address = Union[tuple[Any, ...], str]
+_Address = tuple[Any, ...] | str
 _RetAddress = Any
 _WriteBuffer = bytearray | memoryview
 _CMSG = tuple[int, int, bytes]