Wikibase Lexeme has its own facility to localize language names (which is partly redundant to the localization provided by the cldr extension). This facility should not be used for languages supported by cldr, once these language names are localized there. For languages supported by the cldr extension, see `$additionalLocalizedLanguages`in `WikibaseLexeme.mediawiki-services.php` or for a more up to date list [$languageNames in CldrNamesEn.php](https://gerrit.wikimedia.org/g/mediawiki/extensions/cldr/+/master/CldrNames/CldrNamesEn.php).
This concerns the localization messages like `wikibase-lexeme-language-name-…` defined in `i18n/language-names/….json` and used in `LexemeLanguageNameLookup`.
A/C:
* Localization messages with keys like `wikibase-lexeme-language-name-XXX`, where XXX is a language supported by the cldr extension, are removed from `i18n/language-names/en.json`.
* `$additionalLocalizedLanguages` is removed from `WikibaseLexeme.mediawiki-services.php`