Update news entry

Author: ukarroum

Doc/whatsnew/3.15.rst

@@ -1382,9 +1382,6 @@ xml.parsers.expat
 
   .. _billion laughs: https://en.wikipedia.org/wiki/Billion_laughs_attack
 
-* Add support for `namespace prefixes <https://www.w3.org/TR/xml-names/#dt-prefix>`_.
-  (Contributed by Yassir Karroum in :gh:`118317`.)
-
 
 xml.sax.expatreader
 -----------------