Temporary logging in SecurityDocymentationIT

#48440 fails in a
strange manner (10 users are returned instead of the expected 9)
and this does not replicate locally. Adding this log statement to
temporarily help with troubleshooting and resolving the issue.

Author: jkakavas

client/rest-high-level/src/test/java/org/elasticsearch/client/documentation/SecurityDocumentationIT.java

@@ -203,6 +203,7 @@ public void testGetUsers() throws Exception {
             // 9 users are expected to be returned
             // test_users (3): user1, user2, user3
             // system_users (6): elastic, beats_system, apm_system, logstash_system, kibana, remote_monitoring_user
+            logger.info(users);
             assertThat(users.size(), equalTo(9));
         }