6 files declare their use of ModuleUninstallValidatorInterface in Zircon Profile 8

BookUninstallValidator.php in core/modules/book/src/BookUninstallValidator.php

Contains \Drupal\book\BookUninstallValidator.

ContentUninstallValidator.php in core/lib/Drupal/Core/Entity/ContentUninstallValidator.php

Contains \Drupal\Core\Entity\ContentUninstallValidator.

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

Contains \Drupal\Core\Field\FieldModuleUninstallValidator.

FieldUninstallValidator.php in core/modules/field/src/FieldUninstallValidator.php

Contains \Drupal\field\FieldUninstallValidator.

FilterUninstallValidator.php in core/modules/filter/src/FilterUninstallValidator.php

Contains \Drupal\filter\FilterUninstallValidator.

ForumUninstallValidator.php in core/modules/forum/src/ForumUninstallValidator.php

Contains \Drupal\forum\ForumUninstallValidator.