The NixOS config in this repos is just used to produce a non-trivial derivation
graph that can demonstrate the slowness introduced by the many sequential
QueryPathInfo ops that nix copy --from ssh-ng://... results in.
$ nix path-info --derivation .#nixosConfigurations.test.config.system.build.toplevel
/nix/store/q4bjy0j6jfs2ydp3d8xqx5g8giv5v9mq-nixos-system-test-26.11.20260531.331800d.drv