Surprisingly only been mentioned once, but Chimera! It's weird and strange and brilliant!
If you want something slightly more normal (well, actually, it's not any more normal, just more common), then you can get PostmarketOS installed on anything if you go outside the documentation a little (it's really not hard, pmbootstrap is quite a good utility). If you take that route, I recommend OpenRC as not only is PMOS anti-AI, but so is OpenRC!