[2.7] Delete old expat comment. (GH-9205)

(cherry picked from commit b9bf9d02)
Co-authored-by: Benjamin Peterson <benjamin@python.org>

Modules/Setup.dist

@@ -467,14 +467,6 @@ GLHACK=-Dclear=__GLclear
 #zlib zlibmodule.c -I$(prefix)/include -L$(exec_prefix)/lib -lz
 
 # Interface to the Expat XML parser
-#
-# Expat was written by James Clark and is now maintained by a group of
-# developers on SourceForge; see www.libexpat.org for more
-# information.  The pyexpat module was written by Paul Prescod after a
-# prototype by Jack Jansen.  Source of Expat 1.95.2 is included in
-# Modules/expat/.  Usage of a system shared libexpat.so/expat.dll is
-# not advised.
-#
 # More information on Expat can be found at www.libexpat.org.
 #
 #pyexpat expat/xmlparse.c expat/xmlrole.c expat/xmltok.c pyexpat.c -I$(srcdir)/Modules/expat -DHAVE_EXPAT_CONFIG_H -DUSE_PYEXPAT_CAPI