Nuke sailor_swimsuit_(idolmaster)

BUR #19012 has been rejected.

mass update sailor_swimsuit_(idolmaster) -sailor_bikini -> -sailor_swimsuit_(idolmaster) sailor_bikini
deprecate sailor_swimsuit_(idolmaster)
nuke sailor_swimsuit_(idolmaster)

First of all, the naming of this tag is about sailor_bikini, not sailor_(one-piece)_swimsuit, and it's questionable whether there should be a separate sailor_bikini tag for idolmaster.
Since almost all of the posts are using this tag inside the copyright named idolmaster,
We can find the same result with copyright + sailor_bikini or character + sailor_bikini.

This is a specific and recognizable in-game outfit, I don't think it needs to be deprecated or nuked. It allows people to filter and find Idolmaster characters in other sailor bikini designs (there are currently only a few such posts, but still) and is also cosplayed by characters outside of the franchise.

This bulk update request is pending automatic rejection in 5 days.

This bulk update request has been rejected because it was not approved within 45 days.

The bulk update request #19012 (forum #250455) has been rejected by @DanbooruBot.