Update pyprland.nix

Added suggested changes, to exec the pyprland service from hyprland.

modules/services/pyprland.nix

@@ -49,6 +49,7 @@ in with lib; {
       };
     };
     
+    wayland.windowManager.hyprland.settings.exec-once = [(getExe cfg.package)];
     home.file.".config/hypr/pyprland.toml".source =
       settingsFormat.generate "pyprland-config.toml" cfg.settings;
   };