Nobody knows for certain, even allowing for both the technical and authoritarian definitions of witchcraft. Technically, it is using wisdom embracing both known and unknown or observable and unobservable aspects of Nature to manifest one’s will. Humans have been doing that for at least the past 20,000 years or so, but no one knows who was the first specialist or when this skill was specialized exactly.
The oldest gravesite of someone who was likely a spiritual mediator or “shamaness” was found in Israel. The site is dated to about 12,000 years ago. The earliest archaeological evidence of religion is from 70,000 years ago in Botswana.
If one takes the authoritarian view, that witchcraft is any spiritual practices that are not a part of the established local religion, then whoever decided to give offerings to maybe the Great Clam when the Great Snake was all the rage, would have been the first witch. So witchcraft may be around 70,000 years old.