Change: Don't reinitialise font caches when setting initial interface scale. (#12722)

src/gfx_func.h

@@ -79,6 +79,7 @@ void ChangeGameSpeed(bool enable_fast_forward);
 void DrawMouseCursor();
 void ScreenSizeChanged();
 void GameSizeChanged();
+void UpdateGUIZoom();
 bool AdjustGUIZoom(bool automatic);
 void UndrawMouseCursor();