13 files declare their use of ConfigurableLanguageManagerInterface in Drupal 8

AccountForm.php in core/modules/user/src/AccountForm.php

ConfigTranslationDeleteForm.php in core/modules/config_translation/src/Form/ConfigTranslationDeleteForm.php

ConfigTranslationFormBase.php in core/modules/config_translation/src/Form/ConfigTranslationFormBase.php

ConfigurableLanguage.php in core/modules/language/src/Entity/ConfigurableLanguage.php

ImportForm.php in core/modules/locale/src/Form/ImportForm.php

LanguageBlock.php in core/modules/language/src/Plugin/Derivative/LanguageBlock.php

LanguageFormBase.php in core/modules/language/src/Form/LanguageFormBase.php

LanguageRequestSubscriber.php in core/modules/language/src/EventSubscriber/LanguageRequestSubscriber.php

LocaleConfigManager.php in core/modules/locale/src/LocaleConfigManager.php

LocaleDefaultConfigStorage.php in core/modules/locale/src/LocaleDefaultConfigStorage.php

NegotiationBrowserForm.php in core/modules/language/src/Form/NegotiationBrowserForm.php

NegotiationConfigureForm.php in core/modules/language/src/Form/NegotiationConfigureForm.php

PathProcessorLanguage.php in core/modules/language/src/HttpKernel/PathProcessorLanguage.php