GH-105879: Note exec/eval keyword change in What's New (GH-121831)

Author: ncoghlan

Doc/whatsnew/3.13.rst

@@ -422,6 +422,10 @@ free-threaded build.
 Other Language Changes
 ======================
 
+* The :func:`exec` and :func:`eval` built-ins now accept their ``globals``
+  and ``locals`` namespace arguments as keywords.
+  (Contibuted by Raphael Gaschignard in :gh:`105879`)
+
 * Allow the *count* argument of :meth:`str.replace` to be a keyword.
   (Contributed by Hugo van Kemenade in :gh:`106487`.)