SDK packaging: avoid forcing CGO on Darwin for watch-only functionality

I’m consuming the new Compose Go SDK from `github.com/docker/compose/v5`. My tool does not use file watching, but building on macOS currently forces `CGO_ENABLED=1` due to the watch implementation pulling in an FSEvents-backed watcher.

Would you consider restructuring so that watch is opt-in for SDK consumers?