bpo-44515: handle non-refcounted GC in contextlib tests (GH-26910) (GH-27379)

Co-authored-by: Ɓukasz Langa <lukasz@langa.pl>
(cherry picked from commit a2c45e5bcf9d3dfff9f2699dbc161489897616b5)

Co-authored-by: Nick Coghlan <ncoghlan@gmail.com>
3 files changed