Follow up to variation-selector-not-found glyph Addresses https://github.com/harfbuzz/harfbuzz/pull/4529#discussion_r1769638033 I'm not sure if this is an improvement. By leaving the var-selector as default-ignorable, ligatures can form around it, and the resulting cluster won't make it clear *which* base+var-selector could not be resolved... That doesn't quite help font fallback the way we want. Putting up for review.