test: Fix a test.

This patch removes a wait of `VectorDiff::Set`, as it's not possible to
receive it, this is wrong.

Author: Hywan

testing/matrix-sdk-integration-testing/src/tests/sliding_sync/room.rs

@@ -1016,16 +1016,6 @@ async fn test_room_info_notable_update_deduplication() -> Result<()> {
     sleep(Duration::from_secs(2)).await;
     assert_eq!(bob_room.state(), RoomState::Joined);
 
-    // Room update for join
-    assert_let!(Some(diffs) = stream.next().await);
-    assert_eq!(diffs.len(), 1);
-    assert_matches!(
-        &diffs[0],
-        VectorDiff::Set { index: 0, value: room } => {
-            assert_eq!(room.room_id(), alice_room.room_id());
-        }
-    );
-
     // Sometimes Synapse sends the same message twice. Let's consume useless `Set`…
     // if they arrived before 3s.
     if let Ok(Some(diffs)) = timeout(Duration::from_secs(3), stream.next()).await {