Remove unused mobile shell test variable

Author: pallyoung

packages/web/src/shells/mobile-shell/index.test.tsx

@@ -2273,7 +2273,7 @@ describe("MobileShell Phase 2 workspace", () => {
       return undefined;
     });
 
-    const { store } = renderMobileShell({
+    renderMobileShell({
       initialEntry: "/workspace",
       sessions: [],
       paneLayout: {