Array’s mutation methods can not trigger the vue component view updates

https://multiple-select-live.wenzhixin.net.cn/code/dingwanren/17543

When using v-model to bind an array variable, the MultipleSelect component's view doesn't get updated when calling array methods like push(), pop(), and splice(). However, when I use the native select element, this issue doesn't occur. Also, there is no problem when reassigning a new value to the array variable.