fn adjust_segment_heights(outline: &mut Outline, axis: &mut Axis)
Slightly increase the height of segments when it makes sense to better detect and ignore serifs.
See https://gitlab.freedesktop.org/freetype/freetype/-/blob/57617782464411201ce7bbc93b086c1b4d7d84a5/src/autofit/aflatin.c#L1933