[Nix@NGI] Snix packaged for NGI Forge

Snix is a modern Rust re-implementation of the components of the Nix package manager. Snix modularity & composability allows recombining its parts in novel ways. It also provides library access to Nix data formats and concepts. In the long-run, Snix aims to produce a Nixpkgs-compatible alternative to NixOS/nix with respects to evaluation and building Nix expressions & systems. Note: Snix still is in its early stages of development. None of our current APIs should be considered stable in any...