fix(electron): electron fallback container should not contain tabs header (#10826)

![image.png](https://graphite-user-uploaded-assets-prod.s3.amazonaws.com/T2klNLEk0wxLh4NRDzhk/3e8e4838-7f28-453d-bd7f-32bfa96f09ae.png)

fix double tabs header issue when loading from external url

packages/frontend/core/src/desktop/components/app-container/index.tsx

@@ -64,6 +64,7 @@ const DesktopLayout = ({
   const isInWorkspace = !!workspaceService;
   return (
     <div className={styles.desktopAppViewContainer}>
+      {!fallback ? (
         <div className={styles.desktopTabsHeader}>
           <AppTabsHeader
             left={
@@ -74,6 +75,7 @@ const DesktopLayout = ({
             }
           />
         </div>
+      ) : null}
       <div className={styles.desktopAppViewMain}>
         {fallback ? (
           <AppSidebarFallback />