build(deps-dev): bump @sveltejs/kit from 2.5.2 to 2.21.1 in /frontend

Bumps [@sveltejs/kit](https://github.com/sveltejs/kit/tree/HEAD/packages/kit) from 2.5.2 to 2.21.1.
- [Release notes](https://github.com/sveltejs/kit/releases)
- [Changelog](https://github.com/sveltejs/kit/blob/main/packages/kit/CHANGELOG.md)
- [Commits](https://github.com/sveltejs/kit/commits/@sveltejs/[email protected]/packages/kit)

---
updated-dependencies:
- dependency-name: "@sveltejs/kit"
  dependency-version: 2.21.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

frontend/package.json

@@ -17,7 +17,7 @@
 	"devDependencies": {
 		"@playwright/test": "^1.51.1",
 		"@sveltejs/adapter-node": "^5.2.12",
-		"@sveltejs/kit": "^2.5.0",
+		"@sveltejs/kit": "^2.21.1",
 		"@sveltejs/vite-plugin-svelte": "^3.1.2",
 		"@tailwindcss/typography": "^0.5.10",
 		"@typescript-eslint/eslint-plugin": "^7.4.0",