Argument 2 passed to _readonlymode_form_list_check() must be of the type array, string given

Patch attached

We are using this patch now that the https://www.drupal.org/project/readonlymode/issues/3224538 🐛 Config schema errors Fixed has been applied.

Works as intended.

This should be a high priority as this causes a fatal error in PHP 8+.

Patch #2 works for me using Drupal 10.3.6 and PHP 8.3
Same result for altcom_neil in the above comment, so moving this issue to RTBC.