[Validator] Remove specific check for Valid targets

Author: ogizanagi

Mapping/ClassMetadata.php

@@ -14,7 +14,6 @@
 use Symfony\Component\Validator\Constraint;
 use Symfony\Component\Validator\Constraints\GroupSequence;
 use Symfony\Component\Validator\Constraints\Traverse;
-use Symfony\Component\Validator\Constraints\Valid;
 use Symfony\Component\Validator\Exception\ConstraintDefinitionException;
 use Symfony\Component\Validator\Exception\GroupDefinitionException;
 
@@ -183,10 +182,6 @@ public function addConstraint(Constraint $constraint)
             throw new ConstraintDefinitionException(sprintf('The constraint "%s" cannot be put on classes.', \get_class($constraint)));
         }
 
-        if ($constraint instanceof Valid) {
-            throw new ConstraintDefinitionException(sprintf('The constraint "%s" cannot be put on classes.', \get_class($constraint)));
-        }
-
         if ($constraint instanceof Traverse) {
             if ($constraint->traverse) {
                 // If traverse is true, traversal should be explicitly enabled