Fix: `<link rel="alternate">`を追って照会するのはOKレスポンスが返却された場合のみに

[kakkokari-gtyih]

What

Why

Additional info (optional)

Checklist

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

[github-actions[bot]]

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

[KisaragiEffective]

メモ: sourceはシンプルに「ダウンしてる時に追うのはよくない」と言っている

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 5 lines in your changes missing coverage. Please review.

Project coverage is 39.57%. Comparing base (9d3a331) to head (dc3aa90). Report is 3 commits behind head on develop.

Files with missing lines	Patch %	Lines
...s/backend/src/core/activitypub/ApRequestService.ts	0.00%	5 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #14627 +/- ## =========================================== - Coverage 39.67% 39.57% -0.10% =========================================== Files 1542 1542 Lines 192781 192785 +4 Branches 2475 3540 +1065 =========================================== - Hits 76492 76302 -190 - Misses 115726 115886 +160 - Partials 563 597 +34 ```

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[syuilo]

🙏🏻