This broke in https://github.com/emilk/egui/pull/3172
Since 0.24.1, `stable_dt` has been fixed at 1/60s, which is a little bit
_too_ stable.
The code issue was the logic for asking "Is this the result of an
immeditate repaint?" was completely broken (always returning false).
* Closes https://github.com/emilk/egui/issues/3830