MDL-76129 made it possible to use the static cache in certain scenarios when caching is otherwise disabled.

However - it provides this cache by directly returning an instance of cachestore_static rather than via cache_application/session/request.

As a result - get_versioned is not available to be called on the cache. Currently this isn't directly an issue for core - but there are some third party plugins that do stuff during install (namely adding instances of activities to the front page) that result in a call to get_versioned on the cache.

By instead providing a cache_application backed by cachestore_static - the cache is presented in the way it normally would be (namely, has the get_versioned capability).