As a user I want to use the REST API on my Wikibase instance, in order to build/use tools which use the content in a Wikibase Cloud instance.
**Current situation**
Wikibase Cloud is currently running 1.39 which is a long way behind Wikidata and therefore the REST API features are different (routes: [1.39](https://github.com/wikimedia/mediawiki-extensions-Wikibase/blob/REL1_39/repo/rest-api/routes.json) - [master](https://github.com/wikimedia/mediawiki-extensions-Wikibase/blob/master/repo/rest-api/routes.json)). Currently we (@Tarrow) believe that if we were to enable this it would be more confusing for users than leaving it disabled.
Given that the next version of MW that Wikibase.cloud updates to is likely to be the next LTS release that will hopefully have a 1.0 version of the REST API (i.e. a semi-feature complete one that isn't expected to undergo major changes) it makes sense for us to wait for this. At the earliest this will be is Late 2024 as per the [[ https://www.mediawiki.org/wiki/MediaWiki_1.43 | Mediawiki 1.43 Release Information ]]
**AC**
* update REST API
* enable swagger for each instance
//Hints for devs//
* https://www.wikidata.org/wiki/Wikidata:REST_API
* https://github.com/wikimedia/mediawiki-extensions-Wikibase/tree/master/repo/rest-api
* https://doc.wikimedia.org/Wikibase/master/php/repo_rest-api_README.html ([1.39 version](https://doc.wikimedia.org/Wikibase/REL1_39/php/md_repo_2rest-api_2README.html))