out of my element (#6074)

Co-authored-by: iaada <iaada@users.noreply.github.com>

Robust.UnitTesting/Shared/GameState/VisibilityTest.cs

@@ -22,6 +22,7 @@ public sealed partial class VisibilityTest : RobustIntegrationTest
     public async Task UnknownEntityTest()
     {
         var server = StartServer();
+        await server.WaitIdleAsync();
 
         var xforms = server.System<SharedTransformSystem>();
         var vis = server.System<VisibilitySystem>();