Tablet allocation does not guarantee fairness of
the first replica in the replicas set across dcs.
The lack of this fix cause the following dtest to fail:
repair_additional_test.py::TestRepairAdditional::test_repair_option_pr_multi_dc
Use the tablet_map get_primary_replica or get_primary_replica_within_dc,
respectively to see if this node is the primary replica for each tablet
or not.
Fixes https://github.com/scylladb/scylladb/issues/17752
No backport is required before 6.0 as tablets (and tablet repair) are introduced in 6.0
Closesscylladb/scylladb#18784
* github.com:scylladb/scylladb:
repair: repair_tablets: use get_primary_replica
repair: repair_tablets: no need to check ranges_specified per tablet
locator: tablet_map: add get_primary_replica_within_dc
locator: tablet_map: get_primary_replica: do not copy tablet info
locator: tablet_map: get_primary_replica: return tablet_replica
f133ae945a