invite team to meeting
It doesn't appear to be possible to schedule a meeting without entering an invitee. That said, it also doesn't appear to be possible to invite the Team itself. The latter would be preferable.
Rob Schmidt commented
What would be great to have option to add the meeting invite to a channel, AND add the team as invitees. Then, the meeting will show up in their calendar as busy, so nobody schedules them for that time. Additionally, if you could expand the group in the invitee list, then you could remove people in that team from the invite that the meeting would be more of an FYI or occasional attendance.