poddlers: disable clean-retired-packages poddler
    
    This poddler is tracebacking and spewing to logs:
    
    -rw-r--r--. 1 root root 106G Aug 16 00:02 messages.log
    
    Disabling it for now until someone can look at it.
    
    Signed-off-by: Kevin Fenzi <kevin@scrye.com>