chore(deps): bump the next group with 3 updates (#5382)

Bumps the next group with 3 updates: [next](https://github.com/vercel/next.js), [@next/mdx](https://github.com/vercel/next.js/tree/HEAD/packages/next-mdx) and [eslint-config-next](https://github.com/vercel/next.js/tree/HEAD/packages/eslint-config-next).


Updates `next` from 15.5.6 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](vercel/next.js@v15.5.6...v16.0.0)

Updates `@next/mdx` from 15.5.6 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/next-mdx)

Updates `eslint-config-next` from 15.5.6 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: next
  dependency-version: 16.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: next
- dependency-name: "@next/mdx"
  dependency-version: 16.0.0
  dependency-type: direct:development
  update-type: version-update:semver-major
  dependency-group: next
- dependency-name: eslint-config-next
  dependency-version: 16.0.0
  dependency-type: direct:development
  update-type: version-update:semver-major
  dependency-group: next
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]