fix: horizontal Menu in flex layout

[afc163]

[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
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🔗 Related issue link

close #27240

💡 Background and solution

📝 Changelog

Language	Changelog
🇺🇸 English	Fix Menu inside flexable container will not shrink properly.
🇨🇳 Chinese	修复 Menu 在 flex 容器内不会正常收缩省略的问题。

☑️ 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

[ant-design-bot]

[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 7daa8f2:

Sandbox	Source
antd reproduction template	Configuration
quirky-wing-qq2xx	Issue #27240

[github-actions]

Size Change: -10 B (0%)

Total Size: 792 kB

Filename	Size	Change
./dist/antd.compact.min.css	66.4 kB	-3 B (0%)
./dist/antd.dark.min.css	67.7 kB	-3 B (0%)
./dist/antd.min.css	66.4 kB	-4 B (0%)

ℹ️ View Unchanged

Filename	Size	Change
./dist/antd-with-locales.min.js	314 kB	0 B
./dist/antd.min.js	278 kB	0 B

_{compressed-size-action}

[codecov]

Codecov Report

Merging #27253 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master    #27253   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          389       389           
  Lines         7388      7388           
  Branches      2073      2024   -49     
=========================================
  Hits          7388      7388           

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