Update Changelog for r45209

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45210 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* numeric.c: Fix rdoc for step

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45211 b2dd03c8-39d4-4d8f-98ff-823fe69b080e