14 files declare their use of ConfigurableLanguageManagerInterface

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
install.core.inc in core/includes/install.core.inc
API functions for installing Drupal.
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

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