All 8 template repos are public → GHA-hosted minutes are free, so
there's no cost incentive to stay on the self-hosted Mac mini. The
only reason we started there was to avoid GHA rate limits (memory
feedback_selfhosted_runner); that concern doesn't apply here because:
- Linux/amd64 builds go native on ubuntu-latest (no QEMU emulation
from arm64 → amd64), so builds run ~2-3x faster.
- docker/login-action@v3 + GITHUB_TOKEN handles GHCR auth cleanly,
no Keychain gymnastics needed.
- No queue wait when the Mac mini is busy publishing canvas/platform
or running e2e.
Concretely this change:
- runs-on: [self-hosted, macos, arm64] → ubuntu-latest
- Drops the hand-rolled `auths` config step (macOS Keychain
workaround) in favour of `docker/login-action@v3`.
- Drops `docker/setup-qemu-action` (unnecessary for a linux/amd64
target on an amd64 runner).
- Uses setup-buildx@v3 to match the login-action major version.
Self-hosted Mac mini remains the runner for private-repo workflows
(follow-up PRs will migrate other public-repo workflows in
molecule-core).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>