[Bug Report] el-tabs在子组件中不能动态拿到选项数据，

[ConstancyMan]

Element UI version

2.15.9

OS/Browsers version

单位个人股

Vue version

2.7.10

Reproduction Link

https://github.com/ElemeFE/element/blob/dev/FAQ.md#常见问题

Steps to reproduce

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What is Expected?

https://github.com/ElemeFE/element/blob/dev/FAQ.md#常见问题

What is actually happening?

https://github.com/ElemeFE/element/blob/dev/FAQ.md#常见问题