style: optimize bordered table header scrollbar style

[afc163]

🤔 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?)

👻 What's the background?

继续优化 #17065

💡 Solution

📝 Changelog

Language	Changelog
🇺🇸 English	merged with #17065
🇨🇳 Chinese	和 #17065 一样

☑️ 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

[netlify]

Deploy preview for ant-design ready!

Built with commit 6d2ad5c

https://deploy-preview-17066--ant-design.netlify.com

[codecov]

Codecov Report

Merging #17066 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #17066   +/-   ##
=======================================
  Coverage   95.96%   95.96%           
=======================================
  Files         263      263           
  Lines        7340     7340           
  Branches     2009     2048   +39     
=======================================
  Hits         7044     7044           
  Misses        294      294           
  Partials        2        2

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