QmlDesigner: Fix build for tests

Updating the NodeMetaInfo mock.

Change-Id: Ia3a87095413bb58430d978bb831ed8b808596093
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

tests/unit/mockup/qmldesigner/designercore/include/nodemetainfo.h

@@ -77,6 +77,7 @@ public:
     bool isQtQuick3DMaterial() const { return {}; }
     bool isQtQuickLoader() const { return {}; }
     bool isQtQuickItem() const { return {}; }
+    bool isQtQuick3DTexture() const { return {}; }
 
     QString importDirectoryPath() const { return {}; }