[3.10] bpo-46445, bpo-46519: Re-import typing.NewType (GH-30886)

Partially reverts 65b88d5e01.

Lib/test/test_typing.py

@@ -19,6 +19,7 @@
 from typing import is_typeddict
 from typing import no_type_check, no_type_check_decorator
 from typing import Type
+from typing import NewType
 from typing import NamedTuple, TypedDict
 from typing import IO, TextIO, BinaryIO
 from typing import Pattern, Match