Fix initial open state to prevent undefined type (#1121)

open is not required prop for wcc.Dialog, thus initial value was undefined and type in Python was `None`. Resolved by defining initial state False.

webviz_subsurface/plugins/_simulation_time_series/_views/_subplot_view/_settings/_time_series.py

@@ -116,6 +116,7 @@ def layout(self) -> List[Component]:
                     TimeSeriesSettings.Ids.VECTOR_CALCULATOR_DIALOG
                 ),
                 draggable=True,
+                open=False,
                 max_width="lg",
                 children=[
                     html.Div(