fix two typos that turned text into markup

Doc/whatsnew/whatsnew24.tex

@@ -267,7 +267,7 @@ yellow 5
  were optimized and now run about one-third faster.  The inner
  loops were also optimized for \class{dict} with performance
  boosts to \method{keys()}, \method{values()}, \method{items()},
-\method{\iterkeys()}, \method{\itervalues()}, and \method{iteritems()}.
+\method{iterkeys()}, \method{itervalues()}, and \method{iteritems()}.
 
 \item The machinery for growing and shrinking lists was optimized
  for speed and for space efficiency.  Small lists (under eight elements)