Allow nonfree packages (to keep being able to install nomad).

flake.nix

@@ -20,7 +20,10 @@
       mkNixos = system: modules: nixpkgs.lib.nixosSystem {
         system = system;
         modules = [
-          ({ config, pkgs, ... }: { nixpkgs.overlays = [ overlay-unstable ]; })
+          ({ config, pkgs, ... }: {
+             nixpkgs.overlays = [ overlay-unstable ];
+             nixpkgs.config.allowUnfree = true;
+           })
         ] ++ modules;
         specialArgs = { inherit inputs self; };
       };