fix(core): persist right sidebar open state correctly for desktop (#12953)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Refactor**
* Improved the method for updating the right sidebar's open state to
enhance maintainability. No visible changes to end-user functionality.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/core/src/modules/workbench/services/desktop-state-synchronizer.ts

@@ -80,7 +80,7 @@ export class DesktopStateSynchronizer extends Service {
 
     this.electronApi.events.ui.onToggleRightSidebar(tabId => {
       if (tabId === appInfo?.viewId) {
-        workbench.sidebarOpen$.next(!workbench.sidebarOpen$.value);
+        workbench.setSidebarOpen(!workbench.sidebarOpen$.value);
       }
     });