1. Training AI on copyrighted works is fair use, so it's allowed no matter what the license says.
2. Training AI on copyrighted works is not fair use, so since pretty much every open source license requires attribution (even ones as lax as MIT do; it's only ones that are pretty much PD-equivalent like CC0, WTFPL, and Unlicense that don't) and AI doesn't give attribution, it's already disallowed by all of them.
So in either case, having a license mention AI explicitly wouldn't do any good, and would only make the license fail to comply with the OSD.