refactor loop to numpy call

[jf---]

could be elegant to use a numpy function rather than looping over the numpy arrays

https://github.com/compas-dev/compas_cgal/blob/ebb85356ad2ba23a2db63263c7adbea1388b21b6/src/compas_cgal/skeletonization.py#L53C1-L58C1

    start_points_reshaped = start_points.reshape(-1, 3)
    end_points_reshaped = end_points.reshape(-1, 3)
    edges = np.stack((start_points_reshaped, end_points_reshaped), axis=1)