Updated runtime so emitted Request type is compatible with Request from lib.dom.d.ts

[james-pre]

#1383 Still seems like a common problem. In the issue, I show a solution to the problem. This solution involves a change to the emitted Request in @cloudflare/workers-types/index.d.ts:

  readonly redirected: boolean;
  readonly url: string;
-  readonly webSocket: WebSocket | null;
+  readonly webSocket?: WebSocket;
  readonly cf?: any;
}

It has been mentioned multiple times that these types are generated from the worker runtime. Can the worker runtime be updated so the emitted type changes as shown above? This would resolve many users' problems, without a significant change to the API or tooling.