So you want an LLM that says they don't train on "copyleft" code, even if they do, so you can virtue signal to yourself without facing any kind of real inconvenience?

How about you start by clarifying what you mean by "copyleft" as that's not a standard term, and it means different things to different people. I've seen it used to refer to MIT style licenses, GPL style licenses, and public domain stuff... All of which are very different things.