The previous commit used `debian-aarch64-bohr` for the runs-on
label, but the actual registered label is the full
`actrunner-debian-aarch64-bohr` (per @marfrit on the PR thread).
Without the `actrunner-` prefix the job would have sat in the queue
forever waiting for a runner that doesn't exist.
Renames the label in three places:
- .gitea/workflows/build.yml — the runs-on directive itself.
- debian/.../build-deb.sh — the comment referencing the expected
runner, and the error message printed when the ABI sanity check
trips (so a future debug session lands on the right runner name).
- debian/.../changelog — the -2 entry's prose description.
Pure label rename; no behavioral or build-graph change.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>