8 files declare their use of ComplexDataDefinitionInterface in Drupal 10

EntityDataDefinitionInterface.php in core/lib/Drupal/Core/Entity/TypedData/EntityDataDefinitionInterface.php

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

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

FieldItemBase.php in core/lib/Drupal/Core/Field/FieldItemBase.php

FieldItemDataDefinitionInterface.php in core/lib/Drupal/Core/Field/TypedData/FieldItemDataDefinitionInterface.php

FieldResolver.php in core/modules/jsonapi/src/Context/FieldResolver.php

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

TypedDataDefinitionTest.php in core/tests/Drupal/KernelTests/Core/TypedData/TypedDataDefinitionTest.php