generateVerifyAndChangeEmailLink is unable to create the email action link

### Describe your environment

* Operating System version: _____
* Firebase SDK version: 13.2.0
* Firebase Product: auth
* Node.js version: 22.14.0
* NPM version: 10.9.2

### Describe the problem

_generateVerifyAndChangeEmailLink_ stopped working. Unfortunately I was unable trace what caused it to stop working.

When running following code to change a users email I get following error:
**FirebaseAuthError: INTERNAL ASSERT FAILED: Unable to create the email action link**
```
{
errorInfo: {
code: 'auth/internal-error',
message: 'INTERNAL ASSERT FAILED: Unable to create the email action link'
},
codePrefix: 'auth'
}
```
#### Steps to reproduce:

Create firebase auth user with password and email.
Try to change the email of the user using _generateVerifyAndChangeEmailLink_

#### Relevant Code:

```typescript
import admin from "firebase-admin";

const serviceAccountDev = require("../keys/developmentKey.json");

admin.initializeApp({
credential: admin.credential.cert(serviceAccountDev),
});

const changeMail = async (email: string, newEmail: string) => {
const changeMailLink = await admin
.auth()
.generateVerifyAndChangeEmailLink(email, newEmail);
console.log("changeMailLink", changeMailLink);
};

```

Inizia riproducendo il malfunzionamento dal punto di ingresso generateVerifyAndChangeEmailLink usando l'esempio TypeScript e la versione indicata del Firebase SDK. Traccia l'implementazione di Admin Node.js Auth e la relativa richiesta email-action-link; il lavoro è completato quando la modifica dell'email di un utente produce un link invece di auth/internal-error.

Scritto dal modello di indicizzazione a partire dal testo della issue.