investigate broken onyx workflow

[idigs]

Onyx workflow halts with a spack error:

. ./spack/share/spack/setup-env.sh
  spack env activate ./KORC/spackenv/excl-milan_linux-ubuntu22.04-zen[3](https://github.com/ORNL-Fusion/KORC/actions/runs/12098728594/job/33735516271#step:5:3)
  spack concretize -f
  spack install
  shell: /usr/bin/bash -leo pipefail {0}
==> Error: No such environment: './KORC/spackenv/excl-milan_linux-ubuntu22.0[4](https://github.com/ORNL-Fusion/KORC/actions/runs/12098728594/job/33735516271#step:5:4)-zen3'

https://github.com/ORNL-Fusion/KORC/actions/runs/12098728594/job/33735516271