Inspired by https://jade.fyi/blog/flakes-arent-real/, this is better for
composability:
> it also doesn't work outside of the flake that's actually invoking nixpkgs.lib.nixosSystem. The latter is the much more sinister part, and the reason I would strongly recommend inline modules with closures instead of specialArgs: they break flake composition.
For now, the `system` remains a specialArg, until I decide what to do
with that.
Trolli Schmittlauch