CSceneViewport: Mark IsHoveringGizmo() as const

This doesn't modify internal member state.

src/Editor/CSceneViewport.cpp

@@ -132,7 +132,7 @@ void CSceneViewport::ResetHover()
     mpHoverNode = nullptr;
 }
 
-bool CSceneViewport::IsHoveringGizmo()
+bool CSceneViewport::IsHoveringGizmo() const
 {
     return mGizmoHovering;
 }

src/Editor/CSceneViewport.h

@@ -65,7 +65,7 @@ public:
     void CheckGizmoInput(const CRay& rkRay);
     SRayIntersection SceneRayCast(const CRay& rkRay);
     void ResetHover();
-    bool IsHoveringGizmo();
+    bool IsHoveringGizmo() const;
 
     void keyPressEvent(QKeyEvent* pEvent) override;
     void keyReleaseEvent(QKeyEvent* pEvent) override;