A “Linux gaming laptop” is just any “gaming” laptop you install Linux on. Ideally use AMD graphics, but even NVIDIA should work fine if you set up the graphics switching properly.
Honestly though, I don’t see a point in a “gaming” laptop these days, just get a Steam Deck and a business class laptop and be done with it. My ThinkPad E495 is still going strong years later, and it might outlive my Steam Deck. I’d much rather replace a cheaper Steam Deck instead of a gaming laptop when it stops keeping up with games.