9 files declare their use of EntityDefinitionTestTrait in Drupal 9

ContentEntityNonRevisionableFieldTest.php in core/tests/Drupal/KernelTests/Core/Entity/ContentEntityNonRevisionableFieldTest.php

ContentModerationStateTest.php in core/modules/content_moderation/tests/src/Kernel/ContentModerationStateTest.php

DefaultTableMappingIntegrationTest.php in core/tests/Drupal/KernelTests/Core/Entity/DefaultTableMappingIntegrationTest.php

EntityDefinitionUpdateTest.php in core/tests/Drupal/KernelTests/Core/Entity/EntityDefinitionUpdateTest.php

EntitySchemaTest.php in core/tests/Drupal/KernelTests/Core/Entity/EntitySchemaTest.php

EntityTestResourceTestBase.php in core/modules/system/tests/modules/entity_test/tests/src/Functional/Rest/EntityTestResourceTestBase.php

FieldableEntityDefinitionUpdateTest.php in core/tests/Drupal/KernelTests/Core/Entity/FieldableEntityDefinitionUpdateTest.php

SqlContentEntityStorageSchemaColumnTest.php in core/modules/field/tests/src/Kernel/Entity/Update/SqlContentEntityStorageSchemaColumnTest.php

ViewsEntitySchemaSubscriberIntegrationTest.php in core/modules/views/tests/src/Kernel/EventSubscriber/ViewsEntitySchemaSubscriberIntegrationTest.php