various: update configs

system/flakes/Styx.nix

@@ -34,7 +34,7 @@ in
       {
         nixpkgs = nixpkgsConfig;
         nix = {
-          nixPath = [ "nixpkgs=${nixpkgs}" ];
+          # nixPath = [ "nixpkgs=${nixpkgs}" ];
           registry.nixpkgs.flake = nixpkgs;
         };
 

system/hosts/Styx.nix

@@ -28,6 +28,7 @@ in
       auto-optimise-store = true;
       keep-derivations = true;
       keep-outputs = true;
+      extra-nix-path = "nixpkgs=flake:nixpkgs";
 
       builders-use-substitutes = true;