fix: .iconfont-size-under-12px not working

[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?)

🔗 Related issue link

close #20752

💡 Background and solution

Fix InputNumber and other components icon size

• InputNumber
• Select
• Dropdown
• Pagination
• Table
• Tabs
• Tree
• Upload
• Cascader

📝 Changelog

Language	Changelog
🇺🇸 English	Fix InputNumber, Select and other components icon size
🇨🇳 Chinese	修复 InputNumber、Select、Table 等组件的图标大小问题。

☑️ 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

[netlify]

Deploy preview for ant-design ready!

Built with commit 1ce2995

https://deploy-preview-20765--ant-design.netlify.com

[codecov]

Codecov Report

Merging #20765 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #20765   +/-   ##
=======================================
  Coverage   97.46%   97.46%           
=======================================
  Files         296      296           
  Lines        6877     6877           
  Branches     1865     1912   +47     
=======================================
  Hits         6703     6703           
  Misses        174      174

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update f3b9a16...1ce2995. Read the comment docs.

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 265c47839dc920dcbfd358f83a23358b26d1c5ac:

Sandbox	Source
antd reproduction template	Configuration

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 1ce2995:

Sandbox	Source
antd reproduction template	Configuration