Update ScriptHandler.php to check for symlinks before creating files directory

When using drupal inside a docker container it can be useful to make the sites/default/files directory a symlink instead. For example here in the wodby documentation https://wodby.com/docs/stacks/drupal/#files_1

I propose adding a check to is_link to prevent errors caused by $fs->exists not handling symlinks.

Author: SkywardRay

scripts/composer/ScriptHandler.php

@@ -53,7 +53,7 @@ public static function createRequiredFiles(Event $event) {
     }
 
     // Create the files directory with chmod 0777
-    if (!$fs->exists($drupalRoot . '/sites/default/files')) {
+    if (!$fs->exists($drupalRoot . '/sites/default/files') && !is_link($drupalRoot . '/sites/default/files')) {
       $oldmask = umask(0);
       $fs->mkdir($drupalRoot . '/sites/default/files', 0777);
       umask($oldmask);