Exclude optional perl(YAML::Any) dependency on EL-5
    
    Upstream took great care to make use of YAML::Any optional¹.  It's fine
    to pull it in on Fedora and EL >= 6, but it's not available for EL-5 so
    we'll just filter it from the requirements.
    
    ¹ git-svn: use YAML format for mergeinfo cache when possible
      https://github.com/git/git/commit/68f532f4b