Revert "Byestring removal for 3.14 (#12490)"

This reverts commit 8a7f09e.

Author: AlexWaygood

stdlib/_collections_abc.pyi

@@ -1,12 +1,13 @@
 import sys
 from abc import abstractmethod
 from types import MappingProxyType
-from typing import (  # noqa: Y022,Y038,UP035
+from typing import (  # noqa: Y022,Y038,UP035,Y057
     AbstractSet as Set,
     AsyncGenerator as AsyncGenerator,
     AsyncIterable as AsyncIterable,
     AsyncIterator as AsyncIterator,
     Awaitable as Awaitable,
+    ByteString as ByteString,
     Callable as Callable,
     ClassVar,
     Collection as Collection,
@@ -59,12 +60,8 @@ __all__ = [
     "ValuesView",
     "Sequence",
     "MutableSequence",
+    "ByteString",
 ]
-if sys.version_info < (3, 14):
-    from typing import ByteString as ByteString  # noqa: Y057,UP035
-
-    __all__ += ["ByteString"]
-
 if sys.version_info >= (3, 12):
     __all__ += ["Buffer"]
 

stdlib/typing.pyi

@@ -923,8 +923,7 @@ class TextIO(IO[str]):
     @abstractmethod
     def __enter__(self) -> TextIO: ...
 
-if sys.version_info < (3, 14):
-    ByteString: typing_extensions.TypeAlias = bytes | bytearray | memoryview
+ByteString: typing_extensions.TypeAlias = bytes | bytearray | memoryview
 
 # Functions