Removing 'mediawiki.ui/variables.less' `@import`, which is now
fully replaced by skin-aware 'mediawiki.skin.variables.less'
standard.
Bumping required MediaWiki core version to >= v1.41.0.
Also
- replacing deprecated keys with new Codex token equivalent keys
Bug: T319381
Bug: T332541
Change-Id: I87bd258a24d8ca8b789f8355fe6495eca4cebb85
This removes CSS selectors associated with the Page tools
feature flag, i.e. `vector-feature-page-tools-disabled` as
well as `vector-feature-page-tools-enabled` by removing
the 'disabled' styles and integrating the 'enabled' styles
into the default page tools code.
Bug: T332090
Change-Id: I382e12ca7ce741a3071582ffa84da03c2ba9e343