In 270094@main, we fixed the case where a scroll container has `pointer-event:none` but some child still reacts to scroll events, but it looks like we're still scrolling the ancestor container when the scrollable child cannot react to scroll events anymore (i.e. we've scrolled to the bottom of the child). Repro video attached. Test case is on https://pages.github.pie.apple.com/ada-cannon/misc/scroll-menu-nohax.html.

This is not necessarily a regression because this was our default (and only) behavior before 270094@main, but now we're doing the right thing initially and _still_ have this buggy behavior.