"
This series hardens raft_group_registry::stop_servers
and uses it to drain_on_shutdown, called before
the database is stopped in cql_test_env.
(Not needed for main).
raft_group_registry deferred_stop is introduced right after
the service is started to make sure it's properly stopped
even if there's an exception at any point while starting.
Test: unit(dev)
"
* tag 'raft_group_registry-drain_on_shutdown-v1' of https://github.com/bhalevy/scylla:
cql_test_env: raft_group_registry::drain_on_shutdown before stopping the database
raft_group_registry: harden stop_servers
raft_group_registry: delete unused _shutdown_gate
964d9e033d