avoid session-scoped fixtures
In !2089 (merged) I had some issues with session-scoped fixtures. So I wanted to check how much of a performance gain we get from them and if it is worth the additional complexity.
I started with
study_groups because they were relatively easy to do. The result (averaged over 10 runs):
- session-scoped: 32.793 s
- not session-scoped: 38.470 s
So the not-session-scoped version takes 17 % longer. IMHO that is enough to justify the complexity.