Remove visible XXX in What's New.

Doc/whatsnew/3.3.rst

@@ -1089,7 +1089,7 @@ datetime
    corresponding to the :class:`~datetime.datetime` instance.
  * The :meth:`datetime.datetime.strftime` method supports formatting years
    older than 1000.
- * XXX The :meth:`datetime.datetime.astimezone` method can now be
+ * The :meth:`datetime.datetime.astimezone` method can now be
    called without arguments to convert datetime instance to the system
    timezone.