If the tree selection box is disabled, the response state of the parent and child will be lost

[rongj]

• I have searched the issues of this repository and believe that this is not a duplicate.

Version

2.1.0

Environment

Reproduction link

Steps to reproduce

动态加载子级或者全部展示子级，如果是禁用disabled或者disableCheckbox状态的会父子级关联选中状态会丢失

What is expected?

即使是禁用状态也保留关联选中或半选中状态，逻辑像其他框架一样https://codepen.io/rongj/pen/xxgGrer

What is actually happening?

子级如果有未选中的项，不论是否可选择 父级的状态都没变化