Bump eslint-config-next from 15.1.7 to 16.0.0 in /frontend

Bumps [eslint-config-next](https://github.com/vercel/next.js/tree/HEAD/packages/eslint-config-next) from 15.1.7 to 16.0.0.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](https://github.com/vercel/next.js/commits/v16.0.0/packages/eslint-config-next)

---
updated-dependencies:
- dependency-name: eslint-config-next
  dependency-version: 16.0.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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Author: dependabot[bot]