Skip macOS GUI Brewfile installs during CI qualification

[Copilot]

The macOS qualification job was failing in the full-install phase when brew bundle attempted to install GUI casks and Mac App Store entries from the repository Brewfile. This change keeps CI validating formula installs while avoiding headless-only package types that are not suitable for GitHub-hosted macOS runners.

• CI-specific Brewfile install behavior

  • Detect macOS GitHub Actions execution in NewMachineSetup.sh.
  • Run brew bundle --verbose with Homebrew Bundle skip flags for casks and MAS entries only in that environment.
  • Preserve the existing full Brewfile install behavior for local runs and non-macOS environments.

• Scope

  • No Brewfile contents were changed.
  • No qualification-stage logic changed outside the macOS CI full-install path.

if is_ci_environment && [ "$(uname -s)" = "Darwin" ]; then
  env HOMEBREW_BUNDLE_NO_INSTALL_CASK=1 \
      HOMEBREW_BUNDLE_NO_INSTALL_MAS=1 \
      brew bundle --verbose
fi