9230913f10
It was added to core MediaWiki long ago for unclear reasons, but it was never actually used for anything, and it's probably not needed anywhere. It was already removed from core MediaWiki, too. ruq-latn and ruq-cyrl should probably be removed, too, but they were actually used for some things in core MediaWiki, so that needs to be cleaned up first. See also downstream bug: https://phabricator.wikimedia.org/T357981