fix build error introduced by merge

Author: KoolADE85

components/dash-core-components/tests/integration/dropdown/test_a11y.py

@@ -99,6 +99,7 @@ def send_keys(key):
     assert num_elements == 100
 
     send_keys(1)  # Expecting to be typing into the searh bar
+    sleep(0.1)  # Wait for search filtering to complete
     num_elements = len(dash_duo.find_elements(".dash-dropdown-option"))
     assert num_elements == 19