Add a site-config

See merge request technical-coordination/project-internal/devops/platform/ebrains-spack-builds!329

BrainScaleS: Update software state

See merge request technical-coordination/project-internal/devops/platform/ebrains-spack-builds!332

This pulls in a few backported build changes that enables building on
non-x86 architectures.
This update introduces compile-time switches to disable building parts
of the low-level software stack which can be skipped for EBRAINS
operation; in particular, the communication modes for non-quiggeldy (the
experiment service) communication with the neuromorphic system are
now disabled conditionally.

Fix stable deployment of BrainScaleS

See merge request technical-coordination/project-internal/devops/platform/ebrains-spack-builds!312

The current stable deployment misses some PPU-related include headers in the
deployment.

update release candidate

See merge request technical-coordination/project-internal/devops/platform/ebrains-spack-builds!310

Add pyunicore

See merge request technical-coordination/project-internal/devops/platform/ebrains-spack-builds!308

NEST dependency update

See merge request technical-coordination/project-internal/devops/platform/ebrains-spack-builds!307

update release candidate

See merge request technical-coordination/project-internal/devops/platform/ebrains-spack-builds!306

Use simpler SDA test

See merge request technical-coordination/project-internal/devops/platform/ebrains-spack-builds!304

update release candidate

See merge request technical-coordination/project-internal/devops/platform/ebrains-spack-builds!303

BrainScaleS: Fix segfault on exit() and provide run environment in install tests

See merge request technical-coordination/project-internal/devops/platform/ebrains-spack-builds!264