feat: Sync Validor stubs with SF6.1

Author: viviengaetan

stubs/Symfony/Component/Validator/ConstraintViolationInterface.stub

@@ -2,6 +2,9 @@
 
 namespace Symfony\Component\Validator;
 
+/**
+ * @method string __toString() Converts the violation into a string for debugging purposes. Not implementing it is deprecated since Symfony 6.1.
+ */
 interface ConstraintViolationInterface
 {
 }

stubs/Symfony/Component/Validator/ConstraintViolationListInterface.stub

@@ -3,8 +3,11 @@
 namespace Symfony\Component\Validator;
 
 /**
+ * @extends \ArrayAccess<int, ConstraintViolationInterface>
  * @extends \Traversable<int, ConstraintViolationInterface>
+ *
+ * @method string __toString() Converts the violation into a string for debugging purposes. Not implementing it is deprecated since Symfony 6.1.
  */
-interface ConstraintViolationListInterface extends \Traversable
+interface ConstraintViolationListInterface extends \Traversable, \Countable, \ArrayAccess
 {
 }