Once WVUI has been deprecated and all of its uses in production code have been removed (see T310243), we should migrate non-production code, then remove WVUI from MediaWiki core.
[x] Migrate production code from WVUI to Codex
[x] Migrate non-production code from WVUI to Codex
[x] {T300595} (extension is not currently deployed in production, only on beta labs; production deployment is blocked on porting to Codex)
[x] {T310240} (extension is deployed, but WVUI code is behind a disabled feature flag in production)
[x] Remove library availability from MediaWiki core
[x] Remove the `wvui` and `wvui-search` modules from Resources.php
[x] Remove `wvui` from `resources/lib/foreign-resources.yaml`
[x] Remove the files in `resources/lib/wvui/` and `resources/src/wvui/`
[ ] Archive repo
[ ] Empty repo
[ ] Drop from CI