removing ckeditor (4)

Problem/Motivation

Seeking to remove CKEditor, receiving: The 'Opigno LMS' install profile requires 'CKEditor 4 (contrib)'
https://opigno.atlassian.net/wiki/spaces/OUM3/pages/3438116866/Upgrade+t... simply states:

Switch the CKEditor module to CKEditor 5:
Enable the CKEditor 5 module.

Steps to reproduce

1. composer create-project opigno/opigno-composer
2. Drupal version: 10.3.10; php 8.3.14; 10.6.20-MariaDB; opigno_module 3.2.8
3. seeking to remove CKEditor 4
4. the Extend UI does not permit CKEditor 4 to be de-selected
5. vendor/drush/drush/drush pmu ckeditor_font: removed a ckeditor (4) dependent module, successfully
6. vendor/drush/drush/drush pmu ckeditor: 'ckeditor: The 'Opigno LMS' install profile requires 'CKEditor 4 (contrib)''

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes