Content Type Designer: Always register root route to support drag-and-drop into empty Generic tab. (#20809)

Always register root route to enable drag-drop on empty Generic tab.

src/Umbraco.Web.UI.Client/src/packages/content/content-type/workspace/views/design/content-type-design-editor.element.ts

@@ -207,7 +207,6 @@ export class UmbContentTypeDesignEditorElement extends UmbLitElement implements
 			});
 		}
 
-		if (this._hasRootGroups || this._tabs.length === 0) {
 		routes.push({
 			path: 'root',
 			component: () => import('./content-type-design-editor-tab.element.js'),
@@ -216,6 +215,8 @@ export class UmbContentTypeDesignEditorElement extends UmbLitElement implements
 				this.#currentTabComponent.containerId = null;
 			},
 		});
+
+		if (this._hasRootGroups || this._tabs.length === 0) {
 			routes.push({
 				path: '',
 				pathMatch: 'full',