32 files declare their use of StorageInterface in Drupal 9

CacheabilityMetadataConfigOverride.php in core/modules/config/tests/config_override_integration_test/src/CacheabilityMetadataConfigOverride.php

ConfigAfterInstallerTestBase.php in core/tests/Drupal/FunctionalTests/Installer/ConfigAfterInstallerTestBase.php

ConfigController.php in core/modules/config/src/Controller/ConfigController.php

ConfigImportForm.php in core/modules/config/src/Form/ConfigImportForm.php

ConfigInstallWebTest.php in core/modules/config/tests/src/Functional/ConfigInstallWebTest.php

ConfigOverride.php in core/lib/Drupal/Core/Installer/ConfigOverride.php

ConfigOverrider.php in core/modules/config/tests/config_entity_static_cache_test/src/ConfigOverrider.php

ConfigOverrider.php in core/modules/settings_tray/tests/modules/settings_tray_override_test/src/ConfigOverrider.php

ConfigOverriderLowPriority.php in core/modules/config/tests/config_override_test/src/ConfigOverriderLowPriority.php

ConfigSchemaChecker.php in core/lib/Drupal/Core/Config/Development/ConfigSchemaChecker.php

ConfigSchemaDiscovery.php in core/lib/Drupal/Core/Config/Schema/ConfigSchemaDiscovery.php

ConfigSingleExportForm.php in core/modules/config/src/Form/ConfigSingleExportForm.php

ConfigSingleImportForm.php in core/modules/config/src/Form/ConfigSingleImportForm.php

ConfigSnapshotSubscriber.php in core/lib/Drupal/Core/EventSubscriber/ConfigSnapshotSubscriber.php

ConfigSync.php in core/modules/config/src/Form/ConfigSync.php

ConfigTestTrait.php in core/tests/Drupal/Tests/ConfigTestTrait.php

DefaultConfigTest.php in core/tests/Drupal/KernelTests/Config/DefaultConfigTest.php

DemoUmamiProfileTest.php in core/profiles/demo_umami/tests/src/Functional/DemoUmamiProfileTest.php

EventSubscriber.php in core/modules/config/tests/config_transformer_test/src/EventSubscriber.php

ExcludedModulesEventSubscriber.php in core/lib/Drupal/Core/EventSubscriber/ExcludedModulesEventSubscriber.php

ExtensionInstallStorageTest.php in core/tests/Drupal/Tests/Core/Config/ExtensionInstallStorageTest.php

FunctionalTestSetupTrait.php in core/lib/Drupal/Core/Test/FunctionalTestSetupTrait.php

LanguageConfigFactoryOverride.php in core/modules/language/src/Config/LanguageConfigFactoryOverride.php

LanguageConfigOverride.php in core/modules/language/src/Config/LanguageConfigOverride.php

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

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

NullStorageTest.php in core/tests/Drupal/Tests/Core/Config/NullStorageTest.php

PirateDayCacheabilityMetadataConfigOverride.php in core/modules/config/tests/config_override_test/src/PirateDayCacheabilityMetadataConfigOverride.php

ReadOnlyStorageTest.php in core/tests/Drupal/Tests/Core/Config/ReadOnlyStorageTest.php

StorageCopyTraitTest.php in core/tests/Drupal/Tests/Core/Config/StorageCopyTraitTest.php

StorageReplaceDataWrapper.php in core/modules/config/src/StorageReplaceDataWrapper.php

StorageReplaceDataWrapperTest.php in core/tests/Drupal/KernelTests/Core/Config/Storage/StorageReplaceDataWrapperTest.php