[Buildkite] Cleanup macOS builders (#17145)
[Buildkite] Cleanup macOS builders (#17145)

macOS builders are reused, so excessive disk usage might lead to
run out of disk space error
ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray