test: let block_gaps_do_not_affect_number_of_events_streamed scanner catchup to live before emitting

Author: 0xNeshi

tests/sync/from_latest.rs

@@ -202,6 +202,8 @@ async fn block_gaps_do_not_affect_number_of_events_streamed() -> anyhow::Result<
     );
     let mut stream = assert_empty!(stream);
 
+    // give scanner time to subscribe to live events
+    sleep(Duration::from_millis(10)).await;
     // Immediately produce a new live event in a new block
     contract.increase().send().await?.watch().await?;