`label` key contains a string. It must be an array

Same issue here after Drupal updates.

I am also getting this issue after upgrade to 10.3 from 10.2.7.

I have created MR by combining issue #3368736 changes here, and using this MR as patch everything is working fine.

"drupal/ckeditor5_font": {
                "3368736 - 'no config schema' Error": "https://git.drupalcode.org/project/ckeditor5_font/-/merge_requests/8.patch",
                "3350333 - TypeError: array_filter(): Argument #1 ($array) must be of type array": "https://www.drupal.org/files/issues/2023-04-21/3350333-5.patch"
            }

Thanks @imran1217!
For me, this combination works for Drupal 10.3.1:

"drupal/ckeditor5_font": {
                "3368736 - 'no config schema' Error": "https://git.drupalcode.org/project/ckeditor5_font/-/merge_requests/8.patch",
                "3350333 - TypeError: array_filter(): Argument #1 ($array) must be of type array": "https://www.drupal.org/files/issues/2023-04-21/3350333-5.patch"
            }

Thanks @imran1217 and @sergiu_

#6 fixed the issue also for me using https://www.drupal.org/project/ckeditor5_font/issues/3368736 🐛 Error after update to Drupal 10.1.0 Active patch.

I close this issue as Duplicate