fix(backend): fix type error(s) in security fixes

[kakkokari-gtyih]

What

Why

Additional info (optional)

CIが通るまで待つ

Checklist

• [x] 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[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

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 43.75000% with 9 lines in your changes missing coverage. Please review.

Project coverage is 39.86%. Comparing base (53e827b) to head (99884c2). Report is 1 commits behind head on develop.

Files with missing lines	Patch %	Lines
packages/backend/src/core/HttpRequestService.ts	16.66%	5 Missing :warning:
...end/src/core/activitypub/models/ApPersonService.ts	66.66%	3 Missing :warning:
...kages/backend/src/core/RemoteUserResolveService.ts	0.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #15009 +/- ## ============================================ + Coverage 19.33% 39.86% +20.53% ============================================ Files 728 1563 +835 Lines 103798 197735 +93937 Branches 991 3634 +2643 ============================================ + Hits 20066 78836 +58770 - Misses 83178 118324 +35146 - Partials 554 575 +21 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

---

🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests
• JS Bundle Analysis - Avoid shipping oversized bundles

[syuilo]

🙏