Login __generated__ file with mutation defined in lowercase is causing errors

Following the official documentation and the rest of the tutorial, queries and mutations are defined with the first letter in uppercase (PascalCase). However, in this [part of the tutorial](https://www.apollographql.com/docs/tutorial/mutations/#define-the-mutation) the mutation `Login` is defined lowercase (I see that in the final version of the tutorial this is corrected):

```gql
export const LOGIN_USER = gql`
mutation login($email: String!) {
login(email: $email)
}
`;
```

The corresponding generated file (`pages/__generated__/login.ts`), `Login` type appears as well in lowercase but the related code is assuming they are in uppercase, throwing errors:

```gql
const [login, { loading, error }] = useMutation<
LoginTypes.Login,
LoginTypes.LoginVariables
>(LOGIN_USER);
```

The mutation `Login` in the integration tests (`server/src/__tests__/integration.js`) is also defined in lowercase:
```gql
const LOGIN = gql`
mutation login($email: String!) {
login(email: $email)
}
`;
```

Examinez la section sur la mutation liée dans l’issue, le fichier généré pages/__generated__/login.ts et server/src/__tests__/integration.js. Vérifiez que le nom de la mutation et les références aux types générés utilisent partout la même casse ; le code du tutoriel et le test d’intégration doivent être cohérents et ne plus produire les erreurs signalées.

Rédigé par le modèle d'indexation à partir du texte de l'issue.