src/vs/workbench/browser/parts/editor/textEditor.ts/AbstractTextEditor/getConfigurationOverrides
class AbstractTextEditor:	protected getConfigurationOverrides(): ICodeEditorOptions {
		const readOnly = this.input?.hasCapability(EditorInputCapabilities.Readonly);

		return {
			overviewRulerLanes: 3,
			lineNumbersMinChars: 3,
			fixedOverflowWidgets: true,
			readOnly,
			renderValidationDecorations: 'on' // render problems even in readonly editors (https://github.com/microsoft/vscode/issues/89057)
		};
	}