adapter: (chrome shim) after 4.1, senders are no longer kept in sync with tracks

Browsers and versions affected Chrome webrtc-adapter >= 4.1.0

Description MediaStream.removeTrack() doesn’t clean up senders.

Steps to reproduce Remove a track from a peer connection’s local stream

Expected results The following assertions hold

let senders = pc.getSenders().filter((s) => s.track.kind === `audio`);
assert.lengthOf(senders, 1);

pc.getLocalStreams().forEach((stream) => {
  stream.getAudioTracks().forEach((t) => {
    stream.removeTrack(t);
  });
});

senders = pc.getSenders().filter((s) => s.track.kind === `audio`);
assert.lengthOf(senders, 0);

Actual results The second assertion above does not hold.