Supporting non nodejs runtimes

### What would you like to see in the library?

1. Remove `jws` and use a different cross-runtime library, to allow for support for workers, bun, web, etc.

### Describe alternatives you've considered

I've considered writing raw HTTP requests for API requests or maintaining a fork of `gtoken`, so that I can use jwt's with googleapis.

### Additional context/notes

`gtoken` is how auth is maintained across all `googleapis` modules. Changing this would effectively allow someone to use most of googleapis with nearly any runtime.

For example, the below ran successfully in a Cloudflare worker

```ts
import { google } from 'googleapis';

const googleAuth = new google.auth.GoogleAuth({
credentials: {
client_email: GOOGLE_SERVICE_ACCOUNT.client_email,
private_key: GOOGLE_SERVICE_ACCOUNT.private_key,
},
scopes: ["https://www.googleapis.com/auth/youtube.readonly"],
});

const youtube = google.youtube({
auth: googleAuth,
version: "v3",
});

const info = await youtube.channels.list({
part: ["snippet", "contentDetails", "statistics"],
id: [YOUTUBE_CHANNEL_ID],
});

console.log("info.data.items:", info.data.items);
```

```
"overrides": {
"gtoken": "github:BjornTheProgrammer/node-gtoken"
}
```

This would greatly broaden the ability to use the `googleapis` npm package, and be incredibly useful for developers. It would reduce the maintenance burden of maintaining unvetted non-standard calls to google's API via fetch requests. And significantly increase the appeal of using google's APIs.