ScrollArea ignores Spacing::scroll_bar_inner_margin for vertical scrollbar

[Barugon]

Describe the bug
I show a ScrollArea after setting Spacing::scroll_bar_inner_margin to 0.0 and here's the result that I get:

Note that the horizontal scrollbar is correct while the vertical scrollbar still has the default margin.

This behavior started with v0.21.

[Barugon]

#2665 seems to be the culprit, specifically this (scroll_area.rs:442):

                    if state.show_scroll[d] {
                        // Make sure content doesn't cover scroll bars
                        let tiny_gap = 1.0;
                        content_clip_rect.max[1 - d] =
                            inner_rect.max[1 - d] + scroll_bar_inner_margin - tiny_gap;
                    }

If I disable that bit of code then it works correctly.