Fix memory leak with the animation player exited with an error

When dropping files onto the player window the animation the player
would restart, freeing everything except for the GHOST_System.
This caused a memory leak in the case of an error, returning without
freeing the system.

Resolve by freeing the system along with everything else.

source/blender/windowmanager/intern/wm_playanim.cc

@@ -2189,6 +2189,8 @@ static std::optional<int> wm_main_playanim_intern(int argc, const char **argv, P
 
   GHOST_DisposeWindow(ps.ghost_data.system, ps.ghost_data.window);
 
+  GHOST_DisposeSystem(ps.ghost_data.system);
+
   /* Early exit, IMB and BKE should be exited only in end. */
   if (ps.argv_next) {
     args_next->argc = ps.argc_next;
@@ -2197,8 +2199,6 @@ static std::optional<int> wm_main_playanim_intern(int argc, const char **argv, P
     return std::nullopt;
   }
 
-  GHOST_DisposeSystem(ps.ghost_data.system);
-
   return EXIT_SUCCESS;
 }