add set state to handle var-exported values

Author: Idrinth

src/DependencyInjection/Definitions/ClassObject.php

@@ -34,7 +34,7 @@ public function isNotUnique(): bool
         return $this->isNotUnique;
     }
 
-    public function __set_state(array $properties)
+    public static function __set_state(array $properties)
     {
         return new ClassObject($properties["id"], $properties["isLazy"], $properties["isNotUnique"]);
     }