14 files declare their use of PageVariant in Page Manager 8.4

FrontPageTest.php in tests/src/Functional/FrontPageTest.php

PageConfigSchemaTest.php in tests/src/Kernel/PageConfigSchemaTest.php

PageManagerAdminTest.php in page_manager_ui/tests/src/Functional/PageManagerAdminTest.php

PageManagerConfigTranslationTest.php in tests/src/Functional/PageManagerConfigTranslationTest.php

PageManagerRoutingTest.php in tests/src/Kernel/PageManagerRoutingTest.php

PageManagerSectionStorage.php in src/Plugin/SectionStorage/PageManagerSectionStorage.php

PageManagerTranslationIntegrationTest.php in tests/src/Functional/PageManagerTranslationIntegrationTest.php

PageNodeAccessTest.php in tests/src/Functional/PageNodeAccessTest.php

PageNodeSelectionTest.php in tests/src/Functional/PageNodeSelectionTest.php

PagePlaceholderTest.php in tests/src/Functional/PagePlaceholderTest.php

PageVariantAddForm.php in page_manager_ui/src/Form/PageVariantAddForm.php

PageVariantPageEntityTest.php in tests/src/Kernel/PageVariantPageEntityTest.php

PageVariantTest.php in tests/src/Unit/PageVariantTest.php

SerializationTest.php in tests/src/Kernel/SerializationTest.php