When modifying a compute environment, we need to create a new one, migrate the pipelines to it, and delete the old one. However, the compute environment needs to be idle before it can be deleted. Users will often relaunch jobs without updating the compute environment, which can make it tedious to delete a compute environment. Adding an option to Disable a compute environment - in other words, to mark it so no new jobs can be started - would make this much easier. We could then create the new environment, migrate the pipelines, mark the old one as disabled, and just wait a day or two for existing jobs to finish.
