Upgrade: Bump loader-utils and next in /ch6/front

Removes [loader-utils](https://github.com/webpack/loader-utils). It's no longer used after updating ancestor dependency [next](https://github.com/vercel/next.js). These dependencies need to be updated together.


Removes `loader-utils`

Updates `next` from 9.5.5 to 13.2.1
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v9.5.5...v13.2.1)

---
updated-dependencies:
- dependency-name: loader-utils
  dependency-type: indirect
- dependency-name: next
  dependency-type: direct:production
...

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

Author: dependabot[bot]