linking/unlinking providers with firebase-admin js sdk not working

### [REQUIRED] Step 2: Describe your environment

* Operating System version: macOS 12.6
* Firebase SDK version: 11.5.0
* Firebase Product: auth
* Node.js version: 16.17.1
* NPM version: 9.4.0

### [REQUIRED] Step 3: Describe the problem

#### Steps to reproduce:

I'm trying to link the email provider to a user.
Code runs without issues, but applies no changes.
Unlinking also not working.

#### Relevant Code:

Scenario:
user is linked to apple and google providers, aim is to unlink those and add email provider instead.

```ts
import * as admin from 'firebase-admin';
process.env['GOOGLE_APPLICATION_CREDENTIALS'] = './firebase_token.json';

admin.initializeApp();
const auth = admin.auth();

const userId = '';
const email = '';

auth.updateUser(userId, {
providersToUnlink: ['apple.com, google.com'],
providerToLink: {
providerId: 'email',
email,
},
})
```

Script exits without issues, changes not applied. User still has apple and google provider but no email provider.