Rotation along plane fails unless collider has non-zero volume

If you create and object perpendicular to the z axis and rotate it around x or y 180 degrees to mirror it (`Quat::from_rotation_x(PI)`), attached colliders stop working if they are flat. For example, this collider breaks: `Collider::cuboid(0.5, 0.5, 0.)`. But this one does not: `Collider::cuboid(0.5, 0.5, 0.1)`.