It doesn't make sense to have a recursive QSet with deleted operator==,
since it's not possible to add elements to it. Consequently declaring a
metatype for it also doesn't make sense. Remove the commented
compile-time check for it.
Task-number: QTBUG-96257
Change-Id: I74ebefb38adcbe36d5c2f317188743e1f37fe16d
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>