improve flaky federation test

[anatawa12]

What

ユーザの削除の待ち時間を伸ばして flaky なテストの改善を試みます

Why

Additional info (optional)

Checklist

• Read the contribution guide
• Test working in a local environment
• (If needed) Add story of storybook
• (If needed) Update CHANGELOG.md
• (If possible) Add tests

[github-actions]

このPRによるapi.jsonの差分
差分はありません。
Get diff files from Workflow Page

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 42.56%. Comparing base (de19d9a) to head (6ec5e7e).
Report is 1 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop   #15845      +/-   ##
===========================================
- Coverage    42.65%   42.56%   -0.09%     
===========================================
  Files         1685     1685              
  Lines       170598   170598              
  Branches      4253     4220      -33     
===========================================
- Hits         72767    72615     -152     
- Misses       97338    97489     +151     
- Partials       493      494       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[syuilo]

🙏