Stop producing the omnigraph-macos-x86_64 archive in both the
stable and edge release workflows. The macos-15-intel runner
build was the slowest of the matrix and Apple Silicon is now
the default Mac developer target.
- release.yml + release-edge.yml: drop the macos-15-intel matrix entry
- install.sh: drop the Darwin/x86_64 case so Intel Macs get a clear
"no prebuilt binary" error instead of attempting an absent download
- update-homebrew-formula.sh: drop the MACOS_X86_* variables and emit
an arm64-only Homebrew formula. The on_macos block now declares
`depends_on arch: :arm64` so Intel `brew install` fails fast with
a clear architecture message instead of installing an arm64 binary
that errors at exec time.
Linux x86_64 build is unaffected.
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>