Missing '-webkit-column-gap'

[Rykus0]

Noted after applying autoprefixer

https://developer.apple.com/library/archive/documentation/AppleApplications/Reference/SafariCSSRef/Articles/StandardCSSProperties.html#//apple_ref/doc/uid/TP30001266--webkit-column-gap

Looks like it might also be in the mdn compatibility data under "multicol_context"
https://github.com/mdn/browser-compat-data/blob/9cdf0da10f6e7bd736ebefc9aae455c501e82a9b/css/properties/column-gap.json#LL157C18-L157C18