[TASK] Remove leftover requireJS implementation of CKEditor

CKEditor does not use RequireJS anymore since
https://review.typo3.org/c/Packages/TYPO3.CMS/+/72733
regardless of any upgrade strategy, this code can be removed

Resolves: #98495
Releases: main
Change-Id: I92e6ebdfef7cb97ee00a1840080db95d9032495d
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75935


Tested-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Benjamin Franzke <bfr@qbus.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Benjamin Franzke <bfr@qbus.de>