EC-CUBE4でradioのNoneの名前を変える方法

            ->add('DeliveryTime', EntityType::class, [
                'class' => 'Eccube\Entity\DeliveryTime',
                'query_builder' => function ($er) {
                    return $er->createQueryBuilder('dt')
                    ->orderBy('dt.sort_no', 'ASC');
                },
                'required' => false,
                'expanded' => true,
                'multiple' => false,
                'mapped' => false,
                'empty_data' => 'null',
                'placeholder' => '指定なし',
            ])

required をnone で placeholder を指定すればいいみたい