feat: Tour support z-index manager

[kiner-tang]

[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
• Workflow
• Other (about what?)

🔗 Related issue link

• 📝[RFC] Support zIndexContext to manage popup's zIndex in Pop-up container #45154

💡 Background and solution

📝 Changelog

Language	Changelog
🇺🇸 English	Tour Support z-index context to manage z-index
🇨🇳 Chinese	漫游式引导组件支持通过 z-index 上下文管理 z-index

☑️ Self-Check before Merge

⚠️ Please check all items below before requesting a reviewing. ⚠️

• 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

---

🚀 Summary

🤖 Generated by Copilot at 79c87b3

Added a custom hook and context for Tour component to handle z-index values. This allows nested descriptions and other components to be layered correctly. Added a test case to verify the behavior.

🔍 Walkthrough

🤖 Generated by Copilot at 79c87b3

• Wrap Tour component with zIndexContext.Provider and pass zIndex prop to RCTour component to use z-index values from context and hook (link)
• Import useZIndex hook and zIndexContext from ../_util/hooks/useZIndex and ../_util/zindexContext respectively (link)
• Add test case to check z-index values of nested Tour and Select components (link)
• Import Select component from antd for test case (link)

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[github-actions]

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size-limit report 📦

Path	Size
./dist/antd.min.js	399.33 KB (+29 B 🔺)
./dist/antd-with-locales.min.js	458.64 KB (+30 B 🔺)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (bff04cd) 100.00% compared to head (d763d84) 100.00%.
Report is 3 commits behind head on refactor-z-index-context.

Additional details and impacted files

@@                    Coverage Diff                     @@
##           refactor-z-index-context    #45425   +/-   ##
==========================================================
  Coverage                    100.00%   100.00%           
==========================================================
  Files                           697       697           
  Lines                         11732     11733    +1     
  Branches                       3137      3137           
==========================================================
+ Hits                          11732     11733    +1     

Files	Coverage Δ
components/tour/index.tsx	100.00% <100.00%> (ø)

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