fix: table selection with empty children error

[zombieJ]

🤔 This is a ...

• New feature
• Bug fix
• Site / document update
• Component style update
• TypeScript definition update
• Refactoring
• Code style optimization
• Test Case
• Branch merge
• Other (about what?)

🔗 Related issue link

fix https://github.com/ant-design/ant-design-pro/issues/5996

💡 Background and solution

📝 Changelog

Language	Changelog
🇺🇸 English	Fix Table selection crash when record children is null.
🇨🇳 Chinese	修复 Table 选择在树形结构子节点为 null 会崩溃的问题。

☑️ Self Check before Merge

• Doc is updated/provided or not needed
• Demo is updated/provided or not needed
• TypeScript definition is updated/provided or not needed
• Changelog is provided or not needed

[tests-checker]

Could you please add tests to make sure this change works as expected?

[ant-design-bot]

[codesandbox-ci]

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[codecov]

Codecov Report

Merging #21528 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master   #21528   +/-   ##
=======================================
  Coverage   97.83%   97.83%           
=======================================
  Files         302      302           
  Lines        7024     7024           
  Branches     1894     1895    +1     
=======================================
  Hits         6872     6872           
  Misses        152      152

Impacted Files	Coverage Δ
components/table/hooks/useLazyKVMap.ts	100% <100%> (ø)	⬆️

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[afc163]

close #21526

close ant-design/pro-table#157