6 files declare their use of MenuInterface in Drupal 10

Menu.php in core/modules/system/src/Entity/Menu.php

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

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

menu_link_content.module in core/modules/menu_link_content/menu_link_content.module

Allows administrators to create custom menu links.

menu_ui.module in core/modules/menu_ui/menu_ui.module

Allows administrators to customize the site's navigation menus.

SystemMenuOffCanvasForm.php in core/modules/system/src/Form/SystemMenuOffCanvasForm.php