Claro toolbar.theme.css aggregation issue

Problem/Motivation

When using claro and CSS aggregation, I am forced to set "preprocess" FALSE to the "css/toolbar.theme.css" file using a "hook_library_info_alter". Otherwise some admin pages likes views edit pages are broken.

While inspecting this file with VSCode, I have found that there is a missing closing } at the of the file, something is not good with it :

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet