losslesscut-bin.x86_64-appimage: fix overriding

Pass attributes `pname` and `version` directly into appimage.wrapType2,
instead of attribute set update ('//'), to ensure that they survive
across overriding.

This is possible as the pname-version passing of buildFHSEnvBubblewrap,
buildFHSEnv, and appimageTools.wrapAppImage is fixed.[1]

[1]: https://github.com/NixOS/nixpkgs/pull/271071

pkgs/applications/video/losslesscut-bin/build-from-appimage.nix

@@ -22,7 +22,7 @@ let
     inherit pname version src;
   };
 in
-(appimageTools.wrapType2 {
+appimageTools.wrapType2 {
   inherit pname version src;
 
   profile = ''
@@ -52,6 +52,4 @@ in
     platforms = [ "x86_64-linux" ];
     mainProgram = "losslesscut";
   };
-}) // {
-  inherit pname version;
 }