fix(seed): Only omit artist name if we know its MBID

The conclusion in 118f0d7 was wrong.
If we have an artist without MBID whose name and credited name are
identical, the artist credit editor on MB had an empty search field.

musicbrainz/seeding.ts

@@ -97,7 +97,7 @@ export function convertArtistCredit(artists?: ArtistCreditName[]): ArtistCreditS
 			const defaultJoinPhrase = (index !== lastIndex) ? (index === lastIndex - 1 ? ' & ' : ', ') : undefined;
 
 			return {
-				artist: artist.name !== artist.creditedName ? { name: artist.name } : undefined,
+				artist: !artist.mbid ? { name: artist.name } : undefined,
 				mbid: artist.mbid,
 				name: artist.creditedName,
 				join_phrase: artist.joinPhrase ?? defaultJoinPhrase,