refactor: cssinjs alert

[xrkffgg]

[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	--
🇨🇳 Chinese	---

☑️ 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]

[github-actions]

Size Change: +927 B (0%)

Total Size: 950 kB

Filename	Size	Change
./dist/antd-with-locales.min.js	377 kB	+1.38 kB (0%)
./dist/antd.compact.min.css	61.8 kB	-459 B (-1%)
./dist/antd.dark.min.css	63.2 kB	-471 B (-1%)
./dist/antd.min.css	61.7 kB	-453 B (-1%)
./dist/antd.min.js	324 kB	+1.38 kB (0%)
./dist/antd.variable.min.css	62.5 kB	-455 B (-1%)

_{compressed-size-action}

[codecov]

Codecov Report

Merging #34285 (1086218) into next (1cd87b4) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##              next    #34285   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          426       426           
  Lines         7866      7872    +6     
  Branches      2271      2276    +5     
=========================================
+ Hits          7866      7872    +6     

Impacted Files	Coverage Δ
components/_util/theme/default.tsx	100.00% <100.00%> (ø)
components/_util/theme/index.tsx	100.00% <100.00%> (ø)
components/_util/theme/util.tsx	100.00% <100.00%> (ø)
components/alert/index.tsx	100.00% <100.00%> (ø)
components/button/button.tsx	100.00% <100.00%> (ø)
components/checkbox/Checkbox.tsx	100.00% <100.00%> (ø)
components/checkbox/Group.tsx	100.00% <100.00%> (ø)
components/config-provider/context.tsx	100.00% <100.00%> (ø)
components/config-provider/index.tsx	100.00% <100.00%> (ø)
components/input/Input.tsx	100.00% <100.00%> (ø)
... and 8 more

---

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[zombieJ]

SSR 好像不全

[zombieJ]

这里改成 ${alertCls}-close-icon，其他地方直接使用 rootCls 都需要替换成 alertCls

[xrkffgg]

input 的 test 先忽略吧

[MadCcc]

master 上 input 有更新，rc-input 更新了个 alpha 版本，正在合到 next，合完了拉一下就行