Remove deprecationWarning for creating an Authenticator without Identifier

This should not give a deprecationWarning as not having an identifier should be a supported configuration for certain identifiers (e.g. Session).

Author: umer936

src/Authenticator/AuthenticatorCollection.php

@@ -67,11 +67,6 @@ protected function _create(object|string $class, string $alias, array $config):
         if (is_string($class)) {
             if (!empty($config['identifier'])) {
                 $this->_identifiers = new IdentifierCollection((array)$config['identifier']);
-            } else {
-                deprecationWarning(
-                    '3.3.0',
-                    'loadIdentifier() usage is deprecated. Directly pass `\'identifier\'` config to the Authenticator.',
-                );
             }
 
             return new $class($this->_identifiers, $config);