Update Doc/whatsnew/3.15.rst

Author: picnixz

Doc/whatsnew/3.15.rst

@@ -148,7 +148,8 @@ wave
 ----
 
 * Removed the ``getmark()``, ``setmark()`` and ``getmarkers()`` methods
-  of the :class:`~wave.Wave_read` and :class:`~wave.Wave_write` classes.
+  of the :class:`~wave.Wave_read` and :class:`~wave.Wave_write` classes,
+  which were deprecated since Python 3.13.
   (Contributed by Bénédikt Tran in :gh:`133873`.)