doc: pytest_collection: has to set `session.items`
doc: pytest_collection: has to set `session.items`

Would make sense to use its return value etc, but this helps for now.

nicoddemus/pytest,nicoddemus/pytest,RonnyPfannschmidt/pytest,Akasurde/pytest,The-Compiler/pytest,markshao/pytest,The-Compiler/pytest,pytest-dev/pytest