That's a very strange extrapolation - we don't need to be any smarter to extract more energy. We're building more renewable energy capability every year, even though humans aren't getting any smarter.

Building a dyson swarm would be a massive project, but modern humans are plenty smart enough to do it. An AI capable of running the project, while beyond the current state of the art, would still not need to be particularly clever. (It doesn't need to design satellites or space factories to get there.)