Some Microsoft Segoe UI Emoji emojis look off

[LaurenzV]

Here is a rather extereme example:

For most other cases it's not there / less extreme, but something is still off. Here is how it's supposed to look:

I still have to figure out whether it's a ttf-parser or a font2svg bug. My plan is to try to implement font2svg for skrifa and see whether the issue exists there as well, in which case it's most likely due to the gradient limitations in SVG.

[RazrFalcon]

Yes, we have to check for Sweep gradients first.