Bump @typescript-eslint/eslint-plugin from 7.18.0 to 8.14.0 in /test-app

Bumps [@typescript-eslint/eslint-plugin](https://github.com/typescript-eslint/typescript-eslint/tree/HEAD/packages/eslint-plugin) from 7.18.0 to 8.14.0.
- [Release notes](https://github.com/typescript-eslint/typescript-eslint/releases)
- [Changelog](https://github.com/typescript-eslint/typescript-eslint/blob/main/packages/eslint-plugin/CHANGELOG.md)
- [Commits](https://github.com/typescript-eslint/typescript-eslint/commits/v8.14.0/packages/eslint-plugin)

---
updated-dependencies:
- dependency-name: "@typescript-eslint/eslint-plugin"
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

test-app/package.json

@@ -66,7 +66,7 @@
     "@types/ember__utils": "^4.0.7",
     "@types/qunit": "^2.19.10",
     "@types/rsvp": "^4.0.9",
-    "@typescript-eslint/eslint-plugin": "^7.18.0",
+    "@typescript-eslint/eslint-plugin": "^8.14.0",
     "@typescript-eslint/parser": "^8.0.1",
     "broccoli-asset-rev": "^3.0.0",
     "concurrently": "^8.2.2",