assets: Avoid bundling "Noto Color Emoji" (~5MB) on iOS

[chrisbobbe]

Noto Color Emoji isn't published in a format that iOS supports: #404 (comment)

We should therefore avoid bundling it on iOS. For discussion of some upstream work that might make it possible to conditionally include/exclude assets, see: #404 (comment)

[gnprice]

For discussion of some upstream work that might make it possible

An update: the two upstream issues linked there are closed. So hopefully we can just use that feature in order to handle this.