Remove unused imports (#752)

Author: spawnia

src/Type/Definition/InputObjectType.php

@@ -8,7 +8,6 @@
 use GraphQL\Language\AST\InputObjectTypeDefinitionNode;
 use GraphQL\Language\AST\InputObjectTypeExtensionNode;
 use GraphQL\Utils\Utils;
-use function call_user_func;
 use function count;
 use function is_array;
 use function is_callable;

src/Validator/Rules/QueryComplexity.php

@@ -20,7 +20,6 @@
 use GraphQL\Type\Definition\FieldDefinition;
 use GraphQL\Validator\ValidationContext;
 use function array_map;
-use function call_user_func_array;
 use function count;
 use function implode;
 use function method_exists;