gh-117945: Fix os.path.ismount() documentation (#117947)

Author: nineteendo

Doc/library/os.path.rst

@@ -302,8 +302,8 @@ the :mod:`glob` module.)
    always mount points, and for any other path ``GetVolumePathName`` is called
    to see if it is different from the input path.
 
-   .. versionadded:: 3.4
-      Support for detecting non-root mount points on Windows.
+   .. versionchanged:: 3.4
+      Added support for detecting non-root mount points on Windows.
 
    .. versionchanged:: 3.6
       Accepts a :term:`path-like object`.