9 files declare their use of ConstraintViolationListInterface in Zircon Profile 8

ContextualValidatorInterface.php in vendor/symfony/validator/Validator/ContextualValidatorInterface.php

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

Contains \Drupal\Core\Entity\EntityConstraintViolationListInterface.

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

Contains \Drupal\Core\Entity\Entity\EntityFormDisplay.

FileWidget.php in core/modules/file/src/Plugin/Field/FieldWidget/FileWidget.php

Contains \Drupal\file\Plugin\Field\FieldWidget\FileWidget.

FilterAPITest.php in core/modules/filter/src/Tests/FilterAPITest.php

Contains \Drupal\filter\Tests\FilterAPITest.

LinkWidget.php in core/modules/link/src/Plugin/Field/FieldWidget/LinkWidget.php

Contains \Drupal\link\Plugin\Field\FieldWidget\LinkWidget.

ValidatorInterface.php in vendor/symfony/validator/Validator/ValidatorInterface.php

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

Contains \Drupal\Core\Field\WidgetBase.

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

Contains \Drupal\Core\Field\WidgetBaseInterface.