use mkConfWrapper for mpv

graphical/mpv.nix

@@ -2,6 +2,7 @@
   pkgs,
   lib,
   config,
+  owoLib,
   ...
 }:
 
@@ -33,14 +34,9 @@ in
 
   config = lib.mkIf cfg.enable {
     environment.systemPackages = [
-      (pkgs.symlinkJoin {
-        inherit name;
-        paths = [ cfg.package ];
-        nativeBuildInputs = [ pkgs.makeWrapper ];
-        postBuild = ''
-          wrapProgram $out/bin/${name} \
-            --add-flags "--config-dir=${pkgs.writeTextDir "${name}.conf" cfg.extraConfig}"
-        '';
+      (owoLib.mkConfWrapper name cfg.package {
+        globalConfig = pkgs.writeTextDir "${name}.conf" cfg.extraConfig;
+        configArg = "--config-dir=";
       })
     ];
   };