You may use this one function instead depricated

    /**
     * Get parameter class
     * @param \ReflectionParameter $parameter
     * @return \ReflectionClass|null
     */
    private function getClass(\ReflectionParameter $parameter):?\ReflectionClass
    {
        $type = $parameter->getType();
        if (!$type || $type->isBuiltin())
            return NULL;

// This line triggers autoloader!
        if(!class_exists($type->getName()))
            return NULL;

       
        return  new \ReflectionClass($type->getName());
    }