Theme settings cannot be saved: logo_text schema type requires a langcode

Problem/Motivation

Saving the theme settings form fails with: "The ui_suite_dsfr.settings config object must specify a language code, because it contains translatable values."

logo_text is declared as type: label (translatable) in config/schema/ui_suite_dsfr.schema.yml, recent core validates on save that a config object holding translatable values carries a langcode, and our config never ships one.

Proposed resolution

Declare logo_text as type: string. This value is the Marianne block text ("République Française"), official brand text that stays in French on every page, so it is not translatable UI text. With no translatable values left in the object, no langcode is required, whatever the site language.

A site that translated logo_text through config translation would lose that translation; per the brand rules this text is not supposed to be translated.