chore(deps): update dependency c8 to v9 (#248)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [c8](https://github.com/bcoe/c8) | [`^8.0.1` -> `^9.0.0`](https://renovatebot.com/diffs/npm/c8/8.0.1/9.0.0) | [![age](https://developer.mend.io/api/mc/badges/age/npm/c8/9.0.0?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://developer.mend.io/api/mc/badges/adoption/npm/c8/9.0.0?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://developer.mend.io/api/mc/badges/compatibility/npm/c8/8.0.1/9.0.0?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://developer.mend.io/api/mc/badges/confidence/npm/c8/8.0.1/9.0.0?slim=true)](https://docs.renovatebot.com/merge-confidence/) |

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### Release Notes

<details>
<summary>bcoe/c8 (c8)</summary>

### [`v9.0.0`](https://github.com/bcoe/c8/blob/HEAD/CHANGELOG.md#900-2024-01-03)

[Compare Source](https://github.com/bcoe/c8/compare/v8.0.1...v9.0.0)

##### ⚠ BREAKING CHANGES

-   **build:** minimum Node.js version is now 14.14.0

##### Features

-   **build:** minimum Node.js version is now 14.14.0 ([2cdc86b](https://github.com/bcoe/c8/commit/2cdc86bd0ac67ecf0f700212dc5f8a830ff9164f))
-   **deps:** update foreground-child to promise API ([#&#8203;512](https://github.com/bcoe/c8/issues/512)) ([b46b640](https://github.com/bcoe/c8/commit/b46b6401274488db5b1027a78090257095ae4f72))
-   **deps:** use Node.js built in rm ([2cdc86b](https://github.com/bcoe/c8/commit/2cdc86bd0ac67ecf0f700212dc5f8a830ff9164f))

</details>

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package.json

@@ -37,7 +37,7 @@
     "@types/mocha": "^9.0.0",
     "@types/node": "^20.4.9",
     "@types/sinon": "^17.0.0",
-    "c8": "^8.0.1",
+    "c8": "^9.0.0",
     "codecov": "^3.0.4",
     "gts": "^5.0.0",
     "mocha": "^9.2.2",