error with DishedVacuumVessel

[shimwell]

spotted this error in the CI

def test_volume_increases_with_rotation_angle():
        test_shape_1 = paramak.DishedVacuumVessel(rotation_angle=180)
        test_shape_2 = paramak.DishedVacuumVessel(rotation_angle=360)
>       assert test_shape_1.volume() * 2 == pytest.approx(test_shape_2.volume())
E       assert 0.0 == 21536838.298035033 ± 2.2e+01
E         comparison failed
E         Obtained: 0.0
E         Expected: 21536838.298035033 ± 2.2e+01