gh-98623: Fix base classes in typing.rst (GH-98626)

(cherry picked from commit 5076108)

Co-authored-by: Nikita Sobolev <mail@sobolevn.me>

Author: miss-islington

Doc/library/typing.rst

@@ -1752,7 +1752,7 @@ Abstract Base Classes
 Corresponding to collections in :mod:`collections.abc`
 """"""""""""""""""""""""""""""""""""""""""""""""""""""
 
-.. class:: AbstractSet(Sized, Collection[T_co])
+.. class:: AbstractSet(Collection[T_co])
 
    A generic version of :class:`collections.abc.Set`.
 
@@ -1808,7 +1808,7 @@ Corresponding to collections in :mod:`collections.abc`
       :class:`collections.abc.KeysView` now supports subscripting (``[]``).
       See :pep:`585` and :ref:`types-genericalias`.
 
-.. class:: Mapping(Sized, Collection[KT], Generic[VT_co])
+.. class:: Mapping(Collection[KT], Generic[KT, VT_co])
 
    A generic version of :class:`collections.abc.Mapping`.
    This type can be used as follows::