fix: InputNumber的onChange的value的类型增加null

[lengfangbing]

[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?)

fix #28759

💡 Background and solution

📝 Changelog

Language	Changelog
🇺🇸 English	Add onChange's value typescript definition null for InputNumber
🇨🇳 Chinese	InputNumber组件的onChange的value的类型增加null

☑️ 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

---

View rendered components/input-number/index.en-US.md
View rendered components/input-number/index.zh-CN.md

[ant-design-bot]

[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 5110c3b:

Sandbox	Source
antd reproduction template	Configuration
基本 - antd@4.10.0	Issue #28759

[github-actions]

Size Change: 0 B

Total Size: 793 kB

ℹ️ View Unchanged

Filename	Size	Change
./dist/antd-with-locales.min.js	315 kB	0 B
./dist/antd.compact.min.css	66.9 kB	0 B
./dist/antd.dark.min.css	68.1 kB	0 B
./dist/antd.min.css	66.9 kB	0 B
./dist/antd.min.js	276 kB	0 B

_{compressed-size-action}