build(deps-dev): bump typescript-eslint from 8.20.0 to 8.21.0

Bumps [typescript-eslint](https://github.com/typescript-eslint/typescript-eslint/tree/HEAD/packages/typescript-eslint) from 8.20.0 to 8.21.0.
- [Release notes](https://github.com/typescript-eslint/typescript-eslint/releases)
- [Changelog](https://github.com/typescript-eslint/typescript-eslint/blob/main/packages/typescript-eslint/CHANGELOG.md)
- [Commits](https://github.com/typescript-eslint/typescript-eslint/commits/v8.21.0/packages/typescript-eslint)

---
updated-dependencies:
- dependency-name: typescript-eslint
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package.json

@@ -71,7 +71,7 @@
     "svelte-check": "^4.1.4",
     "svelte-eslint-parser": "^0.43.0",
     "typescript": "5.7.3",
-    "typescript-eslint": "^8.20.0",
+    "typescript-eslint": "^8.21.0",
     "vite": "^5.4.11",
     "vitest": "^2.1.8"
   },