[3.14] [Docs] Add missing note about Required/NotRequired/ReadOnly in get_type_hints() (pythonGH-139565) (python#140386)

[Docs] Add missing note about Required/NotRequired/ReadOnly in get_type_hints() (pythonGH-139565)
(cherry picked from commit a752f58)

Co-authored-by: Sam Bull <git@sambull.org>

Author: miss-islington

Doc/library/typing.rst

@@ -3360,7 +3360,8 @@ Introspection helpers
      ``__annotations__`` dictionaries. Annotations on classes appearing
      earlier in the :term:`method resolution order` always take precedence over
      annotations on classes appearing later in the method resolution order.
-   * The function recursively replaces all occurrences of ``Annotated[T, ...]``
+   * The function recursively replaces all occurrences of
+     ``Annotated[T, ...]``, ``Required[T]``, ``NotRequired[T]``, and ``ReadOnly[T]``
      with ``T``, unless *include_extras* is set to ``True`` (see
      :class:`Annotated` for more information).