Exclude tools/psalm/vendor from Rector

Author: BenMorel

tools/rector/rector.php

@@ -16,6 +16,7 @@
     ])
     ->withSkip([
         $root . '/tools/ecs/vendor',
+        $root . '/tools/psalm/vendor',
         $root . '/tools/rector/vendor',
 
         // This one does not really match with the project's code style