QtSupport et al: Use more data members in QtVersionFactories

Same pattern as for the project configuration factories.

Change-Id: Ia2f85eb2d787965f7a49be3bfe0be20c3f2aed8a
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/ios/iosqtversionfactory.h

@@ -35,9 +35,6 @@ class IosQtVersionFactory : public QtSupport::QtVersionFactory
 public:
     explicit IosQtVersionFactory(QObject *parent = nullptr);
 
-    bool canRestore(const QString &type) override;
-
-    int priority() const override;
     QtSupport::BaseQtVersion *create(const Utils::FileName &qmakePath, ProFileEvaluator *evaluator,
                                      bool isAutoDetected = false,
                                      const QString &autoDetectionSource = QString()) override;