they are called soccer/football uniforms, NOT kits. kits are a collection of equipment/supplies that are enclosed by containers like boxes/cases/pouches and are organized around a task or activity. (i don't care what the dictionary says).
Replying to @StefanThinks@beige.party
@StefanThinks if you are in North America, sure. Otherwise, "kit" also means "a set of clothes for an athletic activity"; UK children are told to bring their "football kit" or "rugby kit" if it is outdoor-sports day at school.