Before 17f4a151ce the node was marked as
been replaced in join_group0 state, before it actually joins the group0,
so by the time it actually joins and starts transferring snapshot/log no
traffic is sent to it. The commit changed this to mark the node as
being replaced after the snapshot/log is already transferred so we can
get the traffic to the node while it sill did not caught up with a
leader and this may causes problems since the state is not complete.
Mark the node as being replaced earlier, but still add the new node to
the topology later as the commit above intended.
Fixes: scylladb/scylladb#20629
Need to be backported since this is a regression
Closesscylladb/scylladb#20743
* github.com:scylladb/scylladb:
test: amend test_replace_reuse_ip test to check that there is no stale writes after snapshot transfer starts
topology coordinator:: mark node as being replaced earlier
topology coordinator: do metadata barrier before calling finish_accepting_node() during replace
7d8f1d251a