fix: agenix on nix-darwin, update flake.nix

lib/colmenaSystem.nix

@@ -12,7 +12,6 @@
 in
   {
     name,
-    nodes,
     ...
   }: {
     deployment = {

lib/macosSystem.nix

@@ -15,6 +15,7 @@ in
       darwin-modules
       ++ [
         ({lib, ...}: {
+          nixpkgs.pkgs = import nixpkgs {inherit system;};
           # make `nix run nixpkgs#nixpkgs` use the same nixpkgs as the one used by this flake.
           nix.registry.nixpkgs.flake = nixpkgs;
 

lib/nixosSystem.nix

@@ -7,7 +7,7 @@
   nixos-modules,
   home-module,
 }: let
-  username = specialArgs.username;
+  inherit (specialArgs) username;
 in
   nixpkgs.lib.nixosSystem {
     inherit system specialArgs;