fix: Tooltip hidden when title is 0

[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 #20891

💡 Background and solution

📝 Changelog

Language	Changelog
🇺🇸 English	Fix Tooltip hidden when title is 0.
🇨🇳 Chinese	修复 Tooltip title 为 0 时没有显示问题。

☑️ 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

[tests-checker]

Could you please add tests to make sure this change works as expected?

[netlify]

Deploy preview for ant-design ready!

Built with commit 3fafca8

https://deploy-preview-20894--ant-design.netlify.com

[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 3fafca8:

Sandbox	Source
antd reproduction template	Configuration

[codecov]

Codecov Report

Merging #20894 into 3.x-stable will increase coverage by <.01%.
The diff coverage is 100%.

@@              Coverage Diff               @@
##           3.x-stable   #20894      +/-   ##
==============================================
+ Coverage       97.81%   97.82%   +<.01%     
==============================================
  Files             286      286              
  Lines            7749     7753       +4     
  Branches         2183     2184       +1     
==============================================
+ Hits             7580     7584       +4     
  Misses            169      169

Impacted Files	Coverage Δ
components/tooltip/index.tsx	96.77% <100%> (+0.14%)	⬆️

---

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 db4bec9...3fafca8. Read the comment docs.