Basically reverting https://github.com/metabrainz/musicbrainz-server/commit/b645483e87b0a08f150a59d813fe807245680d08#diff-7c7b92ca2900a82b2a0167537eface22

relevant conversation log:
[20:35] <yvanzo> reosarevok: I don't recall if it had any practical issue but proposing irrelevant values, what's the point of using these special values in editor's profile?
[20:42] <reosarevok> Fun
[20:42] <reosarevok> It's nice to let our users have fun though :​)
[20:48] <CatQuest> yes!
[20:50] <CatQuest> (also, my profile now says I am native in arabic which I never set and its erroneous (this because I edited my profile recently to add a new email) naturally i didn't notice any language changes)
[20:50] <CatQuest> anyway its a bit of harmless fun. its nice to let users be allowed to do something silly sometimes :​)

[22:56] <Freso> yvanzo reosarevok CatQuest: FWIW, as a dancer and a musician, I do consider myself somewhat capable of communicating on "no linguistic content". I should probably remove some of the "Basic" proficiency ones as those are essentially included in the "[Multiple languages]" one… But both of those are there just as much for fun as they are serious. Same for "artificial languages" (Python, HTML, some C, some JavaScript, some …).