fix(backend): チャート生成時にinstance.isSuspendedが読まれてしまう問題の修正

[tai-cha]

What

13861 の変更に伴ってDB上からはinstanceに対してisSuspendedがなくなったが残っていたのでチャート生成時にエラーが出ていたので置き換えた

Why

参照できない旨のエラーが出ていたため

Additional info (optional)

インスタンス一覧での絞り込みが失敗する問題に関しては#13945 ですでに修正PRがあるので残り部分の修正

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

差分はこちら

```diff ```

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[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.

Project coverage is 64.91%. Comparing base (8f833d7) to head (122ac34).

Files	Patch %	Lines
...ckages/backend/src/core/chart/charts/federation.ts	0.00%	3 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #13951 +/- ## =========================================== - Coverage 65.01% 64.91% -0.10% =========================================== Files 989 989 Lines 112995 112995 Branches 5790 5777 -13 =========================================== - Hits 73460 73352 -108 - Misses 38093 38201 +108 Partials 1442 1442 ```

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[syuilo]

🙏