Remove deprecated systems from teams page
Description
While it's useful to have pages for deprecated systems in case people are not yet aware they are deprecated, it is misleading to have these listed under the team responsibilities as it implies some teams have more services than they actually do.
At a minimum, we ought to make it clear on https://guidebook.devops.uis.cam.ac.uk/home/teams/ if a service is no longer available, but it's probably better to just remove them from there completely or move them to a separate section.