fix(mobile): mounted check before setState in album sync action (#28300)

_manualSyncAlbums fires a setState 1s after sync via Future.delayed
with no mounted check. if the widget is gone by then, setState throws
null check and the global error logger logs it severe.

mobile/lib/widgets/settings/backup_settings/drift_backup_settings.dart

@@ -74,6 +74,7 @@ class _AlbumSyncActionButtonState extends ConsumerState<_AlbumSyncActionButton>
     } catch (_) {
     } finally {
       Future.delayed(const Duration(seconds: 1), () {
+        if (!mounted) return;
         setState(() {
           isAlbumSyncInProgress = false;
         });