signOutUser method
Signs out a user from the server and deletes all authentication keys. This means that the user will be signed out from all connected devices.
Implementation
Future<void> signOutUser({int? userId}) async {
userId ??= await authenticatedUserId;
if (userId == null) return;
await _session.dbNext
.deleteWhere<AuthKey>(where: AuthKey.t.userId.equals(userId));
_session._authenticatedUser = null;
}