build(deps): bump setuptools from 67.8.0 to 68.0.0 in /nix

Bumps [setuptools](https://github.com/pypa/setuptools) from 67.8.0 to 68.0.0.
- [Release notes](https://github.com/pypa/setuptools/releases)
- [Changelog](https://github.com/pypa/setuptools/blob/main/NEWS.rst)
- [Commits](pypa/setuptools@v67.8.0...v68.0.0)

---
updated-dependencies:
- dependency-name: setuptools
  dependency-type: indirect
  update-type: version-update:semver-major
...

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