[checkpoint] Increase timeout to 60s for e2e tests (#4507)

crates/sui/tests/checkpoints_tests.rs

@@ -82,7 +82,7 @@ async fn wait_for_advance_to_next_checkpoint(
             false => sleep(Duration::from_secs(1)).await,
         }
         cnt += 1;
-        assert!(cnt <= 20);
+        assert!(cnt <= 60);
     }
 
     // Ensure all authorities moved to the next checkpoint sequence number.