Schema version 1.6+ ships the Crowdin translation within the extension, because the new translations server for TYPO3 v9 is only used on new TYPO3 installation by default. With schema version 2 the compatibility with TYPO3 v9 is abandoned, so the translations are always taken from the translation server. Therefore, they can be removed from the extension itself.
[x] Remove translation files for other languages than English
Schema version 1.6+ ships the Crowdin translation within the extension, because the new translations server for TYPO3 v9 is only used on new TYPO3 installation by default. With schema version 2 the compatibility with TYPO3 v9 is abandoned, so the translations are always taken from the translation server. Therefore, they can be removed from the extension itself.