hheretic: add missing libGL and libGLU depends (#403458)

pkgs/by-name/hh/hheretic/package.nix

···
   fetchFromGitHub,
   SDL,
   SDL_mixer,
+  libGL,
+  libGLU,
   autoreconfHook,
   gitUpdater,
 }:
···
   buildInputs = [
     SDL
     SDL_mixer
+    libGL
+    libGLU
   ];
 
   strictDeps = true;