Fix implicitly-required parameters

Author: nicolas-grekas

Context/ExecutionContext.php

@@ -152,7 +152,7 @@ public function __construct(ValidatorInterface $validator, $root, TranslatorInte
     /**
      * {@inheritdoc}
      */
-    public function setNode($value, ?object $object, ?MetadataInterface $metadata = null, string $propertyPath)
+    public function setNode($value, ?object $object, ?MetadataInterface $metadata, string $propertyPath)
     {
         $this->value = $value;
         $this->object = $object;

Context/ExecutionContextInterface.php

@@ -129,7 +129,7 @@ public function getObject();
      * @param object|null $object       The currently validated object
      * @param string      $propertyPath The property path to the current value
      */
-    public function setNode($value, ?object $object, ?MetadataInterface $metadata = null, string $propertyPath);
+    public function setNode($value, ?object $object, ?MetadataInterface $metadata, string $propertyPath);
 
     /**
      * Warning: Should not be called by user code, to be used by the validator engine only.