fix pot with handles when pot is rectangle

[xieleo5]

The current pot_with_handles object will result in a wrong shape when size[0] != size[1] One line change can fix this.

[xieleo5]

Code to test

pot = PotWithHandlesObject(
            name="pot",
            body_half_size=[0.16, 0.20, 0.05],
            handle_radius=0.01,
            handle_length=0.06,
            handle_width=0.14,
)

Expected behavior, return a rectangle tray with handles.

Before

After