Bump the next group in /app/frontend with 2 updates

Bumps the next group in /app/frontend with 2 updates: [next](https://github.com/vercel/next.js) and [eslint-config-next](https://github.com/vercel/next.js/tree/HEAD/packages/eslint-config-next).


Updates `next` from 15.2.4 to 15.3.0
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v15.2.4...v15.3.0)

Updates `eslint-config-next` from 15.2.4 to 15.3.0
- [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/v15.3.0/packages/eslint-config-next)

---
updated-dependencies:
- dependency-name: next
  dependency-version: 15.3.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: next
- dependency-name: eslint-config-next
  dependency-version: 15.3.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: next
...

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

Author: dependabot[bot]