Right now, we invite new users to the rust-lang GitHub organization when they are added to a team. Eventually, they might stop contributing to the team and leave it again. When that happens, they are removed from the team in the rust-lang/team repo.

When a user is no longer part of any team or working group, we should also remove them from the rust-lang GitHub organization. This a) cleans up the members of the organization, making it easier to manage and review them. And b) frees up seats in the organization. The latter will become more relevant in the future, when admins will need to manually add seats in case we run out of our current allocation.