Classify the following celebrities as sports or acting personalities or both : Arnold Schwarzenegger, Brad Pitt, Kevin Durant, Shohei Ohtani, Harrison Ford, Dwayne Johnson, Jason Statham, Stephen Curry, Robin Williams, Scarlett Johansson, Tom Brady, Patrick Mahomes

Many athletes are known to do cameos in movies and a have a couple of their own sports related movies. Ignoring those few roles, I would classify the celebrities mentioned as :

Actors who were not sports personalities include Brad Pitt, Harrison Ford, Robin Williams, Scarlett Johansson.

Sports personalities who have not taken up acting as a major career (yet) are :
Kevin Durant - Acted in Thunderstuck and other movies and documentaries, but not a mainstream actor.
Stephen Curry - Did a few cameos and documentaries.
Shohei Ohtani and Patrick Mahomes only appear in sports documentaries and  tv series.
Tom Brady had a major plot role in '80 for Brady' and cameos in other movies, but he is still largely a sports personality.

Actors with successful sports background are : Arnold Schwarzenegger (body building), Dwayne Johnson (Wrestling) and Jason Statham (Diving)