fix test number input

Author: T4rk1n

components/dash-core-components/tests/integration/input/test_number_input.py

@@ -245,7 +245,7 @@ def test_inni010_valid_numbers(dash_dcc, ninput_app):
         (str(sys.float_info.max), float),
         (str(sys.float_info.min), float),
     ):
-        elem = dash_dcc.find_element("#input_false")
+        elem = dash_dcc.wait_for_element("#input_false")
         elem.send_keys(num)
         assert dash_dcc.wait_for_text_to_equal(
             "#div_false", str(op(num))