electrical bundle router doesn't compute lengths

[joamatab]

lengths are reported as 0

this is the failing test

sample_different_factory = """
name: sample_different_factory

instances:
    bl:
      component: pad
    tl:
      component: pad
    br:
      component: pad
    tr:
      component: pad

placements:
    tl:
        x: 0
        y: 200

    br:
        x: 400
        y: 400

    tr:
        x: 400
        y: 600

routes:
    electrical:
        settings:
            port_type: electrical
            separation: 20
            cross_section:
                cross_section: metal3
                settings:
                    width: 10
        links:
            tl,e3: tr,e1
            bl,e3: br,e1
"""


def test_connections_different_factory() -> None:
    c = from_yaml(sample_different_factory)
    c.show()
    lengths = [660000] * 2 + [700000]
    lengths = [0] * 2 + [0]  # TODO: fix this
    assert c.routes["electrical-tl,e3-tr,e1"].length == lengths[0], c.routes[
        "electrical-tl,e3-tr,e1"
    ].length
    assert c.routes["electrical-bl,e3-br,e1"].length == lengths[1], c.routes[
        "electrical-bl,e3-br,e1"
    ].length