Add CI config test

First experiment with podman an docker.io/nixos/nix:latest:

# nix-channel --add https://github.com/nix-community/home-manager/archive/release-23.11.tar.gz home-manager
# nix-channel --add https://github.com/Mic92/sops-nix/archive/master.tar.gz sops-nix
# nix-channel --update
# nix-build "<nixpkgs/nixos>" -I nixos-config=./configuration.nix

Yields error on builder for man-cache.drv

Explore possibilities:

• CI runner with NixOS
• NixOS VM
• Nix/NixOS Container

Resources:

• https://github.com/nix-community/docker-nixpkgs?tab=readme-ov-file#list-of-images
• docker.nix-community.org/nixpkgs/nix