boot: use upstream plymouth themes package

pkgs/default.nix

@@ -2,7 +2,6 @@
 # You can build them using 'nix build .#example' or (legacy) 'nix-build -A example'
 
 { pkgs, inputs }: {
-  plymouth-theme-red = pkgs.callPackage ./plymouth-theme-red.nix { inherit inputs; };
   cargo-checkmate = pkgs.callPackage ./cargo-checkmate.nix { };
   lipsum = pkgs.callPackage ./lipsum.nix { inherit inputs; };
   emmet-cli = pkgs.callPackage ./emmet-cli.nix { };

pkgs/plymouth-theme-red.nix

@@ -1,25 +0,0 @@
-{ pkgs, inputs }:
-pkgs.stdenv.mkDerivation rec {
-  pname = "red-loader-plymouth";
-  version = "0.0.1";
-
-  src = inputs.plymouth-themes;
-
-  buildInputs = [
-    pkgs.git
-  ];
-
-  configurePhase = ''
-    mkdir -p $out/share/plymouth/themes/
-  '';
-
-  buildPhase = ''
-  '';
-
-  installPhase = ''
-    cp -r pack_4/red_loader $out/share/plymouth/themes
-    cat pack_4/red_loader/red_loader.plymouth | sed  "s@\/usr\/@$out\/@" > \
-      $out/share/plymouth/themes/red_loader/red_loader.plymouth
-  '';
-}
-

system/boot.nix

@@ -37,8 +37,10 @@
     plymouth = {
       enable = true;
       theme = lib.mkIf (pkgs.uservars.desktop == "sway") "red_loader";
-      themePackages = [
-        pkgs.plymouth-theme-red
+      themePackages = with pkgs; [
+        (adi1090x-plymouth-themes.override {
+          selected_themes = [ "red_loader" ];
+        })
       ];
     };
   };