tree组件的switcherIcon插件不能获取最后一级的图标

[lllianreg]

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

Version

3.2.20

Environment

vue3.2

Reproduction link

Steps to reproduce

可以从示例代码中看到 icon文本 并没有输出到最后一级（测试数据2-1）这些上面

What is expected?

希望有个插槽能获取最后一级从而修改折叠图标

What is actually happening?

这应该是个bug

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[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.