Mark test_basic_tls_traffic as smoke

Related-prod: PRODX-39931

Change-Id: Ifa2edfb5293b9f996ff7b6b45153ddb4f5939fdd
(cherry picked from commit 297cbdbaf93cf1a74e0691a74ed564ace2b88191)
diff --git a/octavia_tempest_plugin/tests/barbican_scenario/v2/test_tls_barbican.py b/octavia_tempest_plugin/tests/barbican_scenario/v2/test_tls_barbican.py
index 80a6905..32eee13 100644
--- a/octavia_tempest_plugin/tests/barbican_scenario/v2/test_tls_barbican.py
+++ b/octavia_tempest_plugin/tests/barbican_scenario/v2/test_tls_barbican.py
@@ -285,6 +285,7 @@
             CONF.load_balancer.check_interval,
             CONF.load_balancer.check_timeout)
 
+    @decorators.attr(type='smoke')
     @decorators.idempotent_id('887ece26-0f7b-4933-89ab-5bb00b106ee0')
     def test_basic_tls_traffic(self):