fix: avoid locking local spack build cache

This does not appear to be necessary. It was introduced as a way to resolve the exec format errors which were due eager qemu binfmt resets.

assigned to @wdconinc

added 3 commits

• a33ac895...bdba99f7 - 2 commits from branch master
• 0a3fd63c - Merge branch 'master' into 'no-spack-mirror-sharing-locked'

Compare with previous version

added 3 commits

• 0a3fd63c...ccb13ecc - 2 commits from branch master
• 36fbf9e3 - Merge branch 'master' into 'no-spack-mirror-sharing-locked'

Compare with previous version

merged