Fix site config ymerge

See merge request technical-coordination/project-internal/devops/platform/ebrains-spack-builds!366

separate Lab-specific configuration files

See merge request technical-coordination/project-internal/devops/platform/ebrains-spack-builds!348

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