Now that migration is done, I'm going to rename the CirrusSearch project to its real name (see T75746 too). Per IRC, the reason for not renaming was that descriptions weren't migrated. Cirrus has a description so I'm all good. I'll be managing this project myself anyway.
Actually the reason is that people renaming names of extensions should be aware that the links to Phabricator in their wiki page will be broken. See the bottom of the infobox at https://www.mediawiki.org/wiki/Extension:CirrusSearch