ULong is not handled in QSortFilterProxyModel::lessThan

On my machine(Ubuntu2004), QVariant::framValue(uint64_t(1)) results in an ULong variant. I have an ItemModel in which data() returns such variants when sorting, it will be sorted in string order but not integer.

From my local Qt code, the reason looks like QMetaType::ULong is not handled in QAbstractItemModelPrivate::isVariantLessThan().