fix(systems/mottarone): the horrors.

alternatively, rollback nixpkgs to before the latest staging merge.
something (gtk3 or something depending on it) broke jaspersoft studio
and well i need that to work

systems/default.nix

@@ -11,8 +11,9 @@ let
     {
       role,
       system,
+      nixpkgs ? inputs.nixpkgs,
     }:
-    inputs.nixpkgs.lib.nixosSystem {
+    nixpkgs.lib.nixosSystem {
       inherit system;
 
       modules = [
@@ -24,9 +25,10 @@ let
       ];
 
       specialArgs = inputs // {
+        inherit nixpkgs;
         _utils = mkUtils {
           inherit lib;
-          pkgs = inputs.nixpkgs.legacyPackages.${system};
+          pkgs = nixpkgs.legacyPackages.${system};
         };
       };
     };
@@ -51,6 +53,7 @@ in
     mottarone = {
       role = "laptop";
       system = "x86_64-linux";
+      nixpkgs = inputs.nixpkgs-mottarone;
     };
 
     etna = {