chore: Configure unstable Nixpkgs overlay

overlays/default.nix

@@ -28,11 +28,16 @@
   unstable-packages = final: _prev: {
     unstable = import inputs.nixpkgs-unstable {
       system = final.system;
+
       overlays = [
         additions
         modifications
       ];
-      # config.allowUnfree = true;
+
+      config = {
+        allowUnfree = true;
+        allowUnsupportedSystem = true;
+      };
     };
   };
 }