test: strengthen durable behavior coverage after review

crates/irtt-integration-tests/tests/async_client_lifecycle.rs

@@ -381,7 +381,7 @@ fn recv_after_local_close_and_no_test_fails_on_first_poll() {
 }
 
 #[test]
-fn authenticated_async_lifecycle_applies_negotiated_dscp() {
+fn authenticated_async_lifecycle_negotiates_dscp() {
     let key = b"async-lifecycle-key".to_vec();
     let server = InTreeServer::start(ServerConfig::default().with_hmac_key(key.clone()));
     runtime().block_on(async {