Remove the DrupalMediaLibrary::isInternal() method, which returns the same value the method in the parent class returns

@apaderno Not found any method DrupalMediaLibrary::isInternal() like this in media or media library module of core so we can close the issue.

api.drupal.org changed the documentation links, so the ones given in the issue summary had to be updated.
The CKEditor module has been removed from Drupal 10. This issue is still relevant for Drupal 10, if the CKEditor 5 module still implement that method.

I cannot find an equivalent class in Drupal 10 for the CKEditor 5 module.

This is an issue only for Drupal 9.5. I am not sure Drupal 9.5 is still supported, at this point, nor if Drupal 9.x are still fixed.

So unfortunately D9 is EOL and no more releases or fixes for it.

So since this is non existent in D10 going to close out for now.