Plotly colourbar legend not showing max or min value

I have a Plotly chart with a colourbar legend.

I'd like this to go from 0 to 100 with the ticks set every 10.

No matter how I try, the chart always starts the ticks at 10 and ends at 90, removing my top and bottom tick.

How can I ensure that the top and bottom tick are shown?

MWE:

import numpy as np
import plotly.graph_objects as go


x = np.linspace(0, 1, 50)
y = np.linspace(0, 1, 50)
xx, yy = np.meshgrid(x, y)

z = 100*xx*yy

figure = go.Figure()
figure.add_trace(
        go.Contour(
            z=z.flatten(),
            x=xx.flatten(),
            y=yy.flatten(),
            zmin=0,
            zmax=100,
            colorbar_tickvals=np.arange(0, 101, 10),
            colorbar_tickmode='array',
        )
)
figure.update_layout(
    template="simple_white",
)

figure.show()  

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