fix: Add missing import to UpdateUserExtSource AuthProc filt

Description

fix: Add missing import to UpdateUserExtSource AuthProc filt

Missing import caused Error ClassNotFound

lib/Auth/Process/UpdateUserExtSource.php

@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace SimpleSAML\Module\perun\Auth\Process;
 
 use SimpleSAML\Auth\ProcessingFilter;
+use SimpleSAML\Configuration;
 use SimpleSAML\Error\Exception;
 use SimpleSAML\Module;
 use SimpleSAML\Module\perun\ChallengeManager;