[3.14] Doc: remove the invalid type variables of typing.TextIO and BinaryIO (GH-142642) (#142643)

They are not generic classes.
(cherry picked from commit fa1ac90)

Co-authored-by: Roman Donchenko <rdonchen@outlook.com>

Author: miss-islington

Doc/library/typing.rst

@@ -2875,8 +2875,8 @@ ABCs and Protocols for working with I/O
 ---------------------------------------
 
 .. class:: IO[AnyStr]
-           TextIO[AnyStr]
-           BinaryIO[AnyStr]
+           TextIO
+           BinaryIO
 
    Generic class ``IO[AnyStr]`` and its subclasses ``TextIO(IO[str])``
    and ``BinaryIO(IO[bytes])``