QScriptable has non virtual destructor.

The virtual keyword is missing from QScriptable destructor.

This may cause some memory leaks when sublcassing from QScriptable  and compiler warnings.

Extracted from qt-everywhere-src-5.15.2\qtscript\src\script\api\qscriptable.h line 59 to 63:

class Q_SCRIPT_EXPORT QScriptable
{
public:
 QScriptable();
 ~QScriptable();

This should be

class Q_SCRIPT_EXPORT QScriptable
{
public:
 QScriptable();
 virtual ~QScriptable();