Fix data race during palette animation with threaded blitters

src/openttd.cpp

@@ -88,7 +88,6 @@
 
 void CallLandscapeTick();
 void IncreaseDate();
-void DoPaletteAnimations();
 void MusicLoop();
 void ResetMusic();
 void CallWindowGameTickEvent();
@@ -1911,8 +1910,6 @@ void GameLoop()
 		StateGameLoop();
 	}
 
-	if (!_pause_mode && HasBit(_display_opt, DO_FULL_ANIMATION)) DoPaletteAnimations();
-
 	InputLoop();
 
 	SoundDriver::GetInstance()->MainLoop();