graphical/mpv: use extraMakeWrapperArgs instead of wrapping twice

note; this doesn't check for a user configfile anymore,
only using the one in the module.

graphical/mpv.nix

@@ -2,7 +2,6 @@
   pkgs,
   lib,
   config,
-  owoLib,
   ...
 }:
 
@@ -33,9 +32,11 @@ in
 
   config = lib.mkIf cfg.enable {
     environment.systemPackages = [
-      (owoLib.mkConfWrapper name cfg.package {
-        globalConfig = pkgs.writeTextDir "${name}.conf" cfg.extraConfig;
-        configArg = "--config-dir=";
+      (cfg.package.override {
+        extraMakeWrapperArgs = [
+          "--add-flags"
+          "--config-dir=${pkgs.writeTextDir "${name}.conf" cfg.extraConfig}"
+        ];
       })
     ];
   };