ci: dont test aws on all server versions (#4418)

Author: durran

.evergreen/ci_matrix_constants.js

@@ -10,7 +10,7 @@ const LOWEST_LTS = NODE_VERSIONS[0];
 const LATEST_LTS = NODE_VERSIONS[NODE_VERSIONS.length - 1];
 
 const TOPOLOGIES = ['server', 'replica_set', 'sharded_cluster'];
-const AWS_AUTH_VERSIONS = ['latest', '8.0', '7.0', '6.0', '5.0', '4.4'];
+const AWS_AUTH_VERSIONS = ['latest'];
 const TLS_VERSIONS = ['latest', '8.0', '7.0', '6.0', '5.0', '4.4', '4.2'];
 const LB_VERSIONS = MONGODB_VERSIONS.slice(0, MONGODB_VERSIONS.indexOf('5.0') + 1);
 LB_VERSIONS.reverse();