refactor: Apply rector changes

Signed-off-by: GitHub <noreply@github.com>
Signed-off-by: Christian Hartmann <chris-hartmann@gmx.de>

Author: nextcloud-command

rector.php

@@ -8,6 +8,7 @@
 declare(strict_types=1);
 
 use Nextcloud\Rector\Set\NextcloudSets;
+use Rector\Php81\Rector\FuncCall\NullToStrictStringFuncCallArgRector;
 use Rector\Config\RectorConfig;
 
 return RectorConfig::configure()
@@ -23,4 +24,7 @@
 	->withCodeQualityLevel(0)
 	->withSets([
 		NextcloudSets::NEXTCLOUD_32,
+	])
+	->withSkip([
+		NullToStrictStringFuncCallArgRector::class,
 	]);