In text field like Body scroll is not possible in Source mode

Problem/Motivation

In text fields like Body, scroll is not possible in Source mode

Steps to reproduce

Create a node, add text to the Body field. Switch to Source mode and you will note that it is not possible to scroll using the mouse button. The only way to go up and down is to use the arrows. On Facebook forums I've seen others as well, complaing on this issue. It is not ma matter of theme as the problem is there both for Claro and Olivero if used as admin theme, so I assume it is a matter of CKEditor

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet