increased retries for flaky test

tests/test_auto_context.py

@@ -38,7 +38,7 @@ def test_adding_elements_with_async_await(screen: Screen):
         ui.timer(1.1, add_b, once=True)
 
     screen.open('/')
-    for i in range(20):
+    for i in range(40):
         if not '''
 card
   A