By default, cluster tests have skip_wait_for_gossip_to_settle=0 and
ring_delay_ms=0. In tests with gossip topology, it may lead to a race,
where nodes see different state of each other.
In case of test_auth_v2_migration, there are three nodes. If the first
node already knows that the third node is NORMAL, and the second node
does not, the system_auth tables can return incomplete results.
To avoid such a race, this commit adds a check that all nodes see other
nodes as NORMAL before any writes are done.
Refs: #24163Closesscylladb/scylladb#24185
555d897a15