style: 💄 fix PageHeader overflow hidden and responsive style

[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 #22020

💡 Background and solution

📝 Changelog

Language	Changelog
🇺🇸 English	- Remove PageHeader unneccessary overflow: hidden style. - 优化 PageHeader 右侧按钮的响应式表现。
🇨🇳 Chinese	- 移除 PageHeader 中不必要的 overflow: hidden 样式以修复弹层隐藏问题。 - Optimize PageHeader extra buttons responsive design.

☑️ 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

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View rendered components/page-header/demo/content.md

[ant-design-bot]

[codesandbox-ci]

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Latest deployment of this branch, based on commit b0b13cf:

Sandbox	Source
antd reproduction template	Configuration
vibrant-night-k7l8w	Issue #22020

[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 412efba:

Sandbox	Source
antd reproduction template	Configuration
serene-lalande-vtpz5	Issue #22020

[codecov]

Codecov Report

Merging #22030 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #22030   +/-   ##
=======================================
  Coverage   97.96%   97.96%           
=======================================
  Files         306      306           
  Lines        7039     7039           
  Branches     1937     1938    +1     
=======================================
  Hits         6896     6896           
  Misses        143      143

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