security-support-ended.deb9: drop support for ckeditor3
Following discussion at https://lists.debian.org/debian-lts/2022/05/msg00060.html This concerns 'ckeditor3', not 'ckeditor'.
Following discussion at https://lists.debian.org/debian-lts/2022/05/msg00060.html This concerns 'ckeditor3', not 'ckeditor'.