pytest

ab63ebb3 - doctest: inline `_setup_fixtures`, make more similar to `Function`

doctest: inline `_setup_fixtures`, make more similar to `Function` There used to be two callers to `_setup_fixtures()`, now there's only one, so inline it and make `DoctestItem` more similar to `Function`. (Eventually we may want to generalize `TopRequest` from taking `Function` directly to some "fixture-supporting item", removing the remaining `type: ignore` here and allowing plugins to do it in a stable manner).