chore: Remove useless anchor-bg

[zombieJ]

[中文版模板 / Chinese template]

🤔 This is a ...

• New feature
• Bug fix
• Site / documentation update
• Demo update
• Component style update
• TypeScript definition update
• Bundle size optimization
• Performance optimization
• Enhancement feature
• Internationalization
• Refactoring
• Code style optimization
• Test Case
• Branch merge
• Other (about what?)

🔗 Related issue link

💡 Background and solution

📝 Changelog

Language	Changelog
🇺🇸 English	Replace Anchor default background to transparent instead of #FFFFFF.
🇨🇳 Chinese	替换 Anchor 默认背景颜色从 #FFFFFF 改至 transparent。

☑️ Self Check before Merge

⚠️ Please check all items below before review. ⚠️

• 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

[github-actions]

[codecov]

Codecov Report

Merging #30336 (4678b4d) into master (7e0af50) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master    #30336   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          397       397           
  Lines         7522      7522           
  Branches      2105      2105           
=========================================
  Hits          7522      7522           

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[github-actions]

Size Change: +5 B (0%)

Total Size: 830 kB

Filename	Size	Change
./dist/antd.compact.min.css	63.9 kB	+2 B (0%)
./dist/antd.dark.min.css	65.2 kB	+2 B (0%)
./dist/antd.min.css	63.9 kB	+1 B (0%)

ℹ️ View Unchanged

Filename	Size	Change
./dist/antd-with-locales.min.js	339 kB	0 B
./dist/antd.min.js	298 kB	0 B

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