fix: when the children of the table column is falsely still recognized as a column group

[yoyo837]

修复当，外围存在一些逻辑操作columus时如reduce, 会对无效的group 识别为group, 导致列头无法显示（均为空group）

动态组装的columus 肯定会声明column 的children, 比如 {

children: xxx ? yyy : nnn
}

但是代码中使用的in 操作符，会识别为column group

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[codecov]

Codecov Report

Merging #430 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master     #430   +/-   ##
=======================================
  Coverage   99.84%   99.84%           
=======================================
  Files          21       21           
  Lines         638      638           
  Branches      182      182           
=======================================
  Hits          637      637           
  Misses          1        1

Impacted Files	Coverage Δ
src/Header/Header.tsx	100% <100%> (ø)	⬆️
src/hooks/useColumns.tsx	100% <100%> (ø)	⬆️

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[yoyo837]

3.x 可以这么玩。

我只是看同不同意改，不行我就自己delete 一下。

[yoyo837]

非“表格树形数据”的场景是不是可以允许这样好一些？

而且“表格树形数据” 主要是dataSource里相关，跟columns 或者 header 应该不影响。

[zombieJ]

两个不是一件事情，一个是 column 的 children，一个是 nest data 的 children。这个可以改。

另外，不用 columnAlias ，直接代码里 as 就行了。减少尺寸。

[zombieJ]

+ rc-table@7.3.3