add missing return type-hints

Author: xabbuh

src/Symfony/Component/Serializer/Normalizer/AbstractNormalizer.php

@@ -267,10 +267,8 @@ protected function getGroups(array $context): array
 
     /**
      * Is this attribute allowed?
-     *
-     * @return bool
      */
-    protected function isAllowedAttribute(object|string $classOrObject, string $attribute, ?string $format = null, array $context = [])
+    protected function isAllowedAttribute(object|string $classOrObject, string $attribute, ?string $format = null, array $context = []): bool
     {
         $ignoredAttributes = $context[self::IGNORED_ATTRIBUTES] ?? $this->defaultContext[self::IGNORED_ATTRIBUTES];
         if (\in_array($attribute, $ignoredAttributes)) {

src/Symfony/Component/Serializer/Normalizer/GetSetMethodNormalizer.php

@@ -179,7 +179,7 @@ protected function setAttributeValue(object $object, string $attribute, mixed $v
         }
     }
 
-    protected function isAllowedAttribute($classOrObject, string $attribute, ?string $format = null, array $context = [])
+    protected function isAllowedAttribute($classOrObject, string $attribute, ?string $format = null, array $context = []): bool
     {
         if (!parent::isAllowedAttribute($classOrObject, $attribute, $format, $context)) {
             return false;

src/Symfony/Component/Serializer/Normalizer/ObjectNormalizer.php

@@ -186,7 +186,7 @@ protected function getAllowedAttributes(string|object $classOrObject, array $con
         return $allowedAttributes;
     }
 
-    protected function isAllowedAttribute($classOrObject, string $attribute, ?string $format = null, array $context = [])
+    protected function isAllowedAttribute($classOrObject, string $attribute, ?string $format = null, array $context = []): bool
     {
         if (!parent::isAllowedAttribute($classOrObject, $attribute, $format, $context)) {
             return false;