[kvlonge]

Why

GitHub-hosted macOS arm64 runners are capacity constrained: release jobs were cancelled with "The job was not acquired by Runner of type hosted even after multiple attempts", which blocked publishing.

Changes

• The Python fork release cross-compiles the macOS arm64 wheel on the Intel macOS runner. That wheel is checked for its arm64 platform tag and compiled module instead of being installed; every other wheel keeps the install-and-import smoke test.
• macOS arm64 jobs in CI and the release workflow use the explicit macos-15 image instead of macos-latest.

Verification

• A manual run of the release workflow on this branch built and checked every wheel.