[nix]add missing deps to pytest
Sandboxing prevents download of external deps with pip. This commit should fix CI for nixos users.
Prochaines maintenances programmées: lundi 06/05, lundi 03/06, lundi 01/07
Pour plus d'informations: https://doc-si.inria.fr/display/SU/Gitlab
Sandboxing prevents download of external deps with pip. This commit should fix CI for nixos users.