AO3-6211 Exclude tags without posted works from unwrangled bins

[Bilka2]

Issue

https://otwarchive.atlassian.net/browse/AO3-6211

Purpose

Exclude tags that are only used on draft works from the tag wrangling bins for unwrangled tags.

Testing Instructions

See Jira.

Credit

Bilka (he/him)

[Bilka2]

The test failure is in "Fandoms used only on external works should be visible to wranglers." because the external work is not considered a work for has_posted_works. The test was added in AO3-4963.

To me this looks like an acceptable behaviour change, based on informal talk with wranglers it sounds like they don't actively wrangle tags that are only used on external works. So I would propose to remove/adjust this test to expect that fandom tags used only on external works are not visible in the fandom mass bin.

[sarken]

I'll talk to the wrangling chairs who might want to consult with their team!

[sarken]

TW chairs have confirmed not showing external work fandoms would be great, thanks! Do you happen to know if there is also a test that shows bookmark-only tags don't show up in bins even after being sorted (i.e., marked a Relationship tag from the Unsorted bin) and assigned to a fandom? If not, it might be good to add a test for that as well.

[sarken]

This is fine as-is, just two little test-related suggestions since it'll be a while before we can get this merged. (Tag Wrangling is going to be so happy when we do!)