Symfony version(s) affected: >= 4.4

Description

I have a DTO which has constraints. One of them is the UniqueEntity constraint. I have specified the class of the entity to retrieve the good manager. However, the validator tries to retrieve the manager from the class of the DTO (which has not manager and repository).

How to reproduce

/**
 * @UniqueEntity(fields={"email"}, entityClass="App\Entity\Entity")
 */
class Dto
{
    public $email;
}

class Entity
{
   private $email;
}

Add a new entry in the database of entity Entity with email email@symfony.com.

$dto = new Dto();
$dto->email = 'email@symfony.com';
$constraints = $validator->validate($dto);
// One violation expected

Possible Solution

$em = $this->registry->getManagerForClass($constraint->entityClass ?? \get_class($entity));

Additional context

Is it intentional?