add missing use statements

Author: LordSimal

src/Authenticator/AuthenticationRequiredException.php

@@ -17,6 +17,7 @@
 namespace Authentication\Authenticator;
 
 use Cake\Http\Exception\HttpException;
+use function Cake\I18n\__d;
 
 /**
  * An exception for stateless authenticators when credentials are wrong/missing.

src/Authenticator/UnauthenticatedException.php

@@ -18,6 +18,7 @@
 
 use Cake\Http\Exception\HttpException;
 use Throwable;
+use function Cake\I18n\__d;
 
 /**
  * An exception that signals that authentication was required but missing.