An artifact is a term used in digital forensics to refer to any trace left on a system by an adversary. Examples are files, registry keys and event logs.
> Its also anything produced by a artistic production process e.g. in software- aka build-artifacts or documentation.
You can drop "artistic" from that, as it comes with a connotation that doesn't necessarily apply. The first part of the term comes from the more general meaning of ars/art, which would nearly translate into English as "craft".
If you follow the (Latin) origin it is even wider, in Italian artifact is artefatto where while the art (arte) part is as you say, the fatto comes from fare (Latin facere) which translate to "made".
And we say "fatto ad arte" to mean that it is "intentionally made" i.e. artefatto is something that doesn't happen normally or naturally and/or does not exist in nature.
As with all industries that are "birthed" by a mother-field software-security has overloaded the term inherited from its birth place industry.
In this case, its the product produced by the investigation.