fix(3.x): Input.Group 1px bug in vertical layout form

[afc163]

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• New feature
• Bug fix
• Site / document update
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• TypeScript definition update
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🔗 Related issue link

close #20616

💡 Background and solution

📝 Changelog

Language	Changelog
🇺🇸 English	Fix Input.Group inside <Form layout="vertical" > 1px bug.
🇨🇳 Chinese	修复 <Form layout="vertical" > 内 Input.Group 偏上一像素的问题。

☑️ 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

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[codecov]

Codecov Report

Merging #20685 into 3.x-stable will not change coverage.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           3.x-stable   #20685   +/-   ##
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  Coverage       97.81%   97.81%           
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  Files             286      286           
  Lines            7749     7749           
  Branches         2172     2172           
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  Hits             7580     7580           
  Misses            169      169

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[afc163]

https://codesandbox.io/s/antd-reproduction-template-ug1iz

可以了。