integ-tests: do not use EFA instances for head node

The big head node instance type was used to speed up NCCL tests
but we don't need EFA enabled instances for it because we're not enabling it
from the Launch Template.

Signed-off-by: Enrico Usai <[email protected]>

Author: Enrico Usai

tests/integration-tests/tests/efa/test_efa.py

@@ -53,7 +53,7 @@ def test_efa(
     # 2 instances are enough for other EFA tests.
     max_queue_size = 4 if instance in osu_benchmarks_instances else 2
     slots_per_instance = fetch_instance_slots(region, instance)
-    head_node_instance = "c5n.18xlarge" if architecture == "x86_64" else "c6gn.16xlarge"
+    head_node_instance = "c5.18xlarge" if architecture == "x86_64" else "c6g.16xlarge"
     cluster_config = pcluster_config_reader(max_queue_size=max_queue_size, head_node_instance=head_node_instance)
     cluster = clusters_factory(cluster_config)
     remote_command_executor = RemoteCommandExecutor(cluster)