In the Raft-based topology, a decommissioning node is removed from group
0 after the decommission request is considered finished (and the token
ring is updated). Therefore, `check_token_ring_and_group0_consistency`
called just after decommission might fail when the decommissioned node
is still in group 0 (as a non-voter). We deflake all tests that call
`check_token_ring_and_group0_consistency` after decommission in this
commit.
Fixes#25809