use explicit return type

Author: karangattu

tests/playwright/shiny/components/data_frame/edit/app.py

@@ -269,13 +269,16 @@ def country_detail_pop() -> Figure:
         import plotly.express as px
 
         return px.line(
+        fig: Figure = px.line(
             px.data.gapminder(),
             x="year",
             y="lifeExp",
             color="country",
             title="Population Over Time",
         )
 
+        return fig
+
     @summary_data.set_patch_fn
     def upgrade_patch(
         *,