StreamStateSaver: disable copy/move

The class has a user-defined destructor, so it mustn't be copied or
moved (which here is the same as copying).

Amends 3c93286f08.

Pick-to: 6.7 6.6 6.5
Change-Id: I1b23588309654f34aedc0269e1d1c9511ddda2bb
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/corelib/serialization/qdatastream.h

@@ -241,6 +241,7 @@ namespace QtPrivate {
 
 class StreamStateSaver
 {
+    Q_DISABLE_COPY_MOVE(StreamStateSaver)
 public:
     inline StreamStateSaver(QDataStream *s) : stream(s), oldStatus(s->status())
     {