🐛 fixed handling of unfree packages in flake

Signed-off-by: Xaiya Schumin <d.schumin@proton.me>

flake.nix

@@ -1,37 +1,30 @@
 {
   description = "Xaiya's packaged packages";
 
-  inputs = {
-    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
-  };
+  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
 
   outputs =
     { self, nixpkgs }:
     let
-      inherit (nixpkgs) lib;
+      systems = nixpkgs.lib.systems.flakeExposed;
 
-      eachSystem =
-        systems: fn:
-        lib.foldl' (
-          acc: system: lib.recursiveUpdate acc (lib.mapAttrs (_: value: { ${system} = value; }) (fn system))
-        ) { } systems;
+      forAllSystems =
+        function:
+          nixpkgs.lib.genAttrs systems (
+            system: function (
+              import nixpkgs {
+                inherit system;
+                config.allowUnfree = true;
+              }
+            )
+          );
+    in {
+      packages = forAllSystems (pkgs: {
+        discord-music-presence = pkgs.callPackage ./pkgs/discord-music-presence.nix { };
+      });
 
-      systems = lib.systems.flakeExposed;
-    in
-    eachSystem systems (
-      system:
-      let
-        pkgs = nixpkgs.legacyPackages.${system};
-      in
-      {
-        # TODO: add logic for packages
-        packages = {
-          discord-music-presence = pkgs.callPackage ./pkgs/discord-music-presence.nix { };
-        };
-
-        devShells = {
+      devShells = forAllSystems (pkgs: {
           default = pkgs.callPackage ./shell.nix { };
-        };
-      }
-    );
+      });
+    };
 }