remove shift & tap enable multiselect (#9625)

Signed-off-by: 21pages <sunboeasy@gmail.com>

flutter/lib/models/peer_tab_model.dart

@@ -152,7 +152,7 @@ class PeerTabModel with ChangeNotifier {
       // https://github.com/flutter/flutter/issues/101275#issuecomment-1604541700
       // After onTap, the shift key should be pressed for a while when not in multiselection mode,
       // because onTap is delayed when onDoubleTap is not null
-      if ((isDesktop || isWebDesktop) && !_isShiftDown) return;
+      if (isDesktop || isWebDesktop) return;
       _multiSelectionMode = true;
     }
     final cached = _currentTabCachedPeers.map((e) => e.id).toList();