pub fn conjugate(self) -> Self {
        Self {
            x: self.x,
            y: -self.y,
        }
    }
Computes the inverse of the point.
We are using -(x, y) = (x, -y), i.e. the inverse of the group opertion is conjugation
because the norm of every point in the circle is one.
crates/math/src/circle/point.rs