Champion Supreme Clothing Set

It's literally base Mesh. no weights etc. just the Mesh. If you want to "headswap" you can add hands and a head then add a armature to it,
(CATS has a armature preset) so you get the whole armature, line it up then weight paint.
If you're very lazy or don't want to weight paint on your own or want most of it done for you,
put it in Mixamo auto rigger then correct it in blender afterwards.

Doesn't contain any bones any workaround to head swap this to a model?

yo been lookin for that top for ages, ty my dude