Pin py-pynn to 0.9.5
Cf. my comment in https://gitlab.ebrains.eu/akarmas/ebrains-spack-builds/-/merge_requests/17#note_2743 … I still try to enforce a newer PyNN version.
Cf. my comment in https://gitlab.ebrains.eu/akarmas/ebrains-spack-builds/-/merge_requests/17#note_2743 … I still try to enforce a newer PyNN version.