Use Brewfile for macOS setup

[g4challenge]

Switches the macOS setup script to Homebrew Bundle so dependency checks and installs follow current Homebrew behavior from a tracked Brewfile.

Changes

• Add scripts/mac/Brewfile for macOS formula dependencies.
• Replace custom Homebrew install/retry logic with brew bundle check and brew bundle install --no-upgrade.
• Preserve existing --skip-* support through HOMEBREW_BUNDLE_BREW_SKIP.

Checks

• bash -n scripts/mac/mac_setup.sh
• git diff --check origin/main...HEAD
• HOMEBREW_NO_AUTO_UPDATE=1 brew bundle list --file scripts/mac/Brewfile
• HOMEBREW_NO_AUTO_UPDATE=1 HOMEBREW_BUNDLE_BREW_SKIP=... brew bundle check --verbose --file scripts/mac/Brewfile

Not run: pixi run lint / pixi run test; this change is macOS setup-only and the local pixi workspace supports linux-64, not osx-arm64.

[knipknap]

Thanks for the PR! I do not have MacOS, so I cannot test this, so I have to trust you and the CI test 😆 .

Is it good to merge?

[g4challenge]

"It works on my machine" - MacOS with newer 6+ Homebrew works fine. - I would have tried to get pixie running on Mac - but that is in another PR.