Javascript:当其他15个单选按钮被选中时，我如何才能启用该单选按钮？

<input type="radio" class="checkbox"> <!-- 单选按钮1 -->
<input type="radio" class="checkbox"> <!-- 单选按钮2 -->
<!-- ... -->
<input type="radio" class="checkbox"> <!-- 单选按钮15 -->
<input type="radio" id="target" disabled> <!-- 目标单选按钮 -->

var checkboxes = document.querySelectorAll('.checkbox'); // 获取所有的单选按钮
var targetCheckbox = document.getElementById('target'); // 获取目标单选按钮

checkboxes.forEach(function(checkbox) {
  checkbox.addEventListener('change', function() {
    var allChecked = true;
    checkboxes.forEach(function(checkbox) {
      if (!checkbox.checked) {
        allChecked = false;
        return;
      }
    });

    if (allChecked) {
      targetCheckbox.disabled = false;
    } else {
      targetCheckbox.disabled = true;
    }
  });
});