The CKEditor buttons on a text format settings page are not showing their iconography in forced color mode

Problem/Motivation

The problem in this issue was part of https://git.drupalcode.org/project/gin/-/work_items/3506350 over in the Gin queue

The CKEditor settings on a text format for example /admin/config/content/formats/manage/full_html?destination=/admin/config/content/formats the buttons are not showing their iconography in forced color mode.

Steps to reproduce

• Enable forced color mode in for example the microsoft edge devtools. on the rendering tab chose prefers-color-scheme: dark, forced-colors: active, and prefers-contrast:more
• Got to /admin/config/content/formats/manage/full_html?destination=/admin/config/content/formats

Proposed resolution

Ensure that every button is showing its icon

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet