fix(add_remove_dc): Use correct method to get cluster status

Use correct method to get cluster nodes status in disrupt_add_remove_dc
method

Fixes: scylladb#9204

sdcm/nemesis.py

@@ -4744,7 +4744,7 @@ def finalizer(exc_type, *_):
             with temporary_replication_strategy_setter(node) as replication_strategy_setter:
                 new_node = self._add_new_node_in_new_dc()
                 node_added = True
-                status = self.tester.db_cluster.get_node()
+                status = self.tester.db_cluster.get_nodetool_status()
                 new_dc_list = [dc for dc in list(status.keys()) if dc.endswith("_nemesis_dc")]
                 assert new_dc_list, "new datacenter was not registered"
                 new_dc_name = new_dc_list[0]