Add bambu-studio the flatpak nix way

flake.nix

@@ -14,6 +14,11 @@
       url = "github:nix-community/home-manager/release-25.11";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+
+    nix-flatpak = {
+      url = "github:gmodena/nix-flatpak";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
   # This strange syntax is a workaround for the intentional limitations of `flake.nix` files.