chore: Fix TS define of FormItem

[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

ref #21065

💡 Background and solution

📝 Changelog

Language	Changelog
🇺🇸 English	Fix Form.Item return type define.
🇨🇳 Chinese

☑️ 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

[ant-design-bot]

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[codecov]

Codecov Report

Merging #21067 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master   #21067   +/-   ##
=======================================
  Coverage   97.48%   97.48%           
=======================================
  Files         296      296           
  Lines        6911     6911           
  Branches     1918     1907   -11     
=======================================
  Hits         6737     6737           
  Misses        174      174

Impacted Files	Coverage Δ
components/form/FormItem.tsx	98.96% <100%> (ø)	⬆️

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[AO19]

Update ant-design/icons to 4.0.0-rc.0 , most of the examples and packages are still at vesion 2...

[zombieJ]

What's means of version 2?