Bump Homebrew/actions/setup-homebrew from 2026.09.07.1 to 2026.09.21.1 in the github-actions group - #5

You are using macOS on Intel x86_64. We do not provide support for this platform (as-of September 2026, announced August 2025). Apple have dropped Intel x86_64 support in macOS Golden Gate (27). GitHub Actions are dropping macOS Intel x86_64 runners in 2027. Homebrew is a non-profit project run entirely by volunteers, not employees. If the biggest companies in the world cannot support macOS Intel x86_64 any longer, sadly neither can we. Homebrew no longer builds bottles for this configuration. Consider MacPorts, which provides binary packages for this macOS version: https://www.macports.org