ProtectedUserFieldConstraint.php

<?php

namespace Drupal\user\Plugin\Validation\Constraint;

use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\Validation\Attribute\Constraint;
use Symfony\Component\Validator\Constraint as SymfonyConstraint;

/**
 * Checks if the plain text password is provided for editing a protected field.
 */
class ProtectedUserFieldConstraint extends SymfonyConstraint {
    
    /**
     * Violation message.
     *
     * @var string
     */
    public $message = "Your current password is missing or incorrect; it's required to change the %name.";

}