Counter example, the book that is the foundation of much coursework and learning for people in AI, has a whole section on "Machine Learning" with all that k-means and such in there - https://aima.cs.berkeley.edu/
I'm really not sure how that's a counterexample. The section is called machine learning, not AI. Machine learning is a useful tool for artificial intelligence, so I'd be surprised if a book about AI did not talk about it.
I'm saying that Machine Learning was borne of AI from the very beginning. ML has become specialized enough that we may later (much much later) declare it somehow larger/separate/overlapping, but it originated from AI as the generic umbrella.
