7 files declare their use of MenuParentFormSelectorInterface in Drupal 9

MenuController.php in core/modules/menu_ui/src/Controller/MenuController.php

MenuLinkContentForm.php in core/modules/menu_link_content/src/Form/MenuLinkContentForm.php

MenuLinkDefaultForm.php in core/lib/Drupal/Core/Menu/Form/MenuLinkDefaultForm.php

MenuLinkDefaultFormTest.php in core/tests/Drupal/Tests/Core/Menu/MenuLinkDefaultFormTest.php

Node.php in core/modules/node/src/Plugin/views/wizard/Node.php

Page.php in core/modules/views/src/Plugin/views/display/Page.php

WizardPluginBase.php in core/modules/views/src/Plugin/views/wizard/WizardPluginBase.php