vtkUnstructuredGrid: remove deprecation of GetCellTypes
This API is also present in vtkDataSet. It was not deprecated there,
and it is a core API. It is just better to rewind this deprecation.
Backport of !9928 (merged)
Backport: paraview/release
This API is also present in vtkDataSet. It was not deprecated there,
and it is a core API. It is just better to rewind this deprecation.
Backport of !9928 (merged)
Backport: paraview/release