Add elimination of non-int-like parameters in math.factorial to "What's new"

Author: pablogsal

Doc/whatsnew/3.8.rst

@@ -201,6 +201,9 @@ Removed
 * Removed the ``doctype()`` method of :class:`~xml.etree.ElementTree.XMLParser`.
   (Contributed by Serhiy Storchaka in :issue:`29209`.)
 
+* The function :func:`math.factorial` no longer accepts arguments that are not
+  int-like. (Contributed by Pablo Galindo in :issue:`33083`.)
+
 
 Porting to Python 3.8
 =====================