There’s not much point.
Angora goat fibre, aka mohair, has its own qualities. It’s primarily used for making suits as it’s quite hardy, but it’s not usually suitable for next-to-skin garments.
Meanwhile, in the sheep world, there’s a humongous range of qualities. Merino and Blue-faced Leicester for under-clothing and babywear, Wensleydale for silk-like, drapey clothing, Icelandic for sturdy cold-weather outerwear, Shetland for lightweight but warm socks and sweaters, Scottish Blackfaced for carpetting, through to mixed-breed meat-sheep’s scraggly fleece that’s only good for house insulation or composting.
Goat genes would add nothing that isn’t already available in one or other sheep breed.