[infra][magnum][ci] Issues installing bashate and coverage

Hello infra,

openstack-tox-lower-constraints fails for bashate and coverage. (Maybe more, I bumped bashate and it failed for coverage. I don;t want to waste more resources on our CI) eg https://review.opendev.org/c/openstack/magnum/+/765881 https://review.opendev.org/c/openstack/magnum/+/765979

Do we miss something?

Thanks, Spyros