Fix/button icon loading not working

[RedJue]

[中文版模板 / Chinese template]

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• [ ] New feature
• [x] Bug fix
• [ ] Site / documentation update
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• [ ] TypeScript definition update
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🔗 Related issue link

fix #40282

💡 Background and solution

📝 Changelog

Language	Changelog
🇺🇸 English	Fix Button icon rotation animation not working when using iconPrefixCls
🇨🇳 Chinese	修复在用 iconPrefixCls 时，按钮加载图标动画丢失问题

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• [ ] Doc is updated/provided or not needed
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