Readd pynn-brainscales (new version)
This should fix the build error encountered in: https://gitlab.ebrains.eu/technical-coordination/project-internal/devops/platform/ebrains-spack-builds/-/jobs/20672
This should fix the build error encountered in: https://gitlab.ebrains.eu/technical-coordination/project-internal/devops/platform/ebrains-spack-builds/-/jobs/20672
merged
mentioned in commit 5a673a51