QCborMap::ConstIterator and Iterator: Add missing destructor

Axivion (SV403 and SV404) points out, based on rule of three,
the lack of destructors for ConstIterator and Iterator.
So add them.

Task-number: QTBUG-122619
Pick-to: 6.7 6.5
Change-Id: I4d4abf9be8be529492bf13069052ae4a8d8a90de
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/serialization/qcbormap.h

@@ -40,6 +40,7 @@ public:
 
         constexpr Iterator() = default;
         constexpr Iterator(const Iterator &) = default;
+        ~Iterator() = default;
         Iterator &operator=(const Iterator &other)
         {
             // rebind the reference
@@ -100,6 +101,7 @@ public:
 
         constexpr ConstIterator() = default;
         constexpr ConstIterator(const ConstIterator &) = default;
+        ~ConstIterator() = default;
         ConstIterator &operator=(const ConstIterator &other)
         {
             // rebind the reference