Skip all wxDPIChangedEvent

So base classes will process the event too.
This is need for (at least) wxGenericColourButton It has its own handler,
but also needs to handle the DPI event in wxButtonImageData.

src/generic/datavgen.cpp

@@ -5682,6 +5682,8 @@ void wxDataViewCtrl::OnDPIChanged(wxDPIChangedEvent& event)
             width = event.ScaleX(width);
         m_cols[i]->SetWidth(width);
     }
+
+    event.Skip();
 }
 
 void wxDataViewCtrl::SetFocus()