so when I use a docker_environment to do the build, the container is left running. This is presumably to speed up builds. But at the end of the builds we do actually produce it would be nice to spin down the containers. Is there an easy want to do this via pants? If not, is there a way to clearly identify the image target so we can shut it down? We are using this on a CI machine and having those resources contiuously spun up will cause build issues with other projects.