Drop the auth modules main's PR 4331 added under src

The SDK replaced `src/livekit` and the remote-member modules before that PR
landed on `main`, so its `src/livekit/auth/*` and `remoteMembers/ConnectionMap.ts`
have no consumer here: the same code lives under `sdk/src/media-backend/livekit`.
The imports of them that `main` added to the view model, the developer
settings tab and the test utils go with them.

src/state/media/MemberMediaViewModel.ts

@@ -34,7 +34,6 @@ import {
 import { type BaseMediaViewModel, createBaseMedia } from "./MediaViewModel";
 import { type UserMediaViewModel } from "./UserMediaViewModel";
 import { type ScreenShareViewModel } from "./ScreenShareViewModel";
-import { type UnstableLivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
 
 /** How often a view model reads a track's RTP statistics while it needs them. */
 export const statsIntervalMs = 1000;