**Reason**: {rEANN} is marked as unmaintained and unstable on mediawiki.org and no development is happening on it. The maintainer seems unresponsive to Tasks at #mediawiki-extensions-annotator too.
- [x] Archive documentation on `mediawiki.org`
- [x] Remove from `mediawiki/extensions` / `mediawiki/skins` (along with in `.gitmodules`)
- [x] Remove tests in `integration/config` (`zuul/layout.yaml`)
- [x] Remove from `translatewiki` (`groups/MediaWiki/mediawiki-extensions.txt`)
- [ ] Remove manifest/other references from `mediawiki/vagrant` if they exist
- [ ] Empty repository and add a `OBSOLETE` file.
- [ ] Archive Phabricator project #mediawiki-extensions-annotator for associated extension/skin
- [ ] Edit Phabricator project #mediawiki-extensions-annotator description for associated extension/skin with a link to this ticket
- [ ] Archive the extension's diffusion repository: {rEANN}
- [ ] Mark the repository read-only in Gerrit.
- [ ] Delete the GitHub mirror: https://github.com/wikimedia/mediawiki-extensions-Annotator