electron-builder overwrites latest-mac.yml when parallel arm64/x64
builds publish independently — whichever finishes last wins, leaving
the other architecture's users downloading the wrong binary.
Add a finalize-mac-manifest job that runs after both macOS builds
complete, merges their per-arch manifest artifacts into a single
latest-mac.yml containing all files, and uploads it to the release.
Mohamed Boudra
4b93f990d2