The new meta capabilities are called `install_languages` and `update_languages`. Prior to this change, there were no proper capability checks applied. Instead only the filesystem and related constants were checked, and for actual permissions a rather vague fallback was used where a user needed to have at least one of the other updating capabilities. In addition to being generally more verbose, the new capabilities make it possible for example to allow a user to update languages, but nothing else. By default they fall back to the original way of how they were handled.
Props johnbillion, flixos90.
Fixes#39677.
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