comment out code that causes out-of-bounds indexing warnings

[akva2]

this code is never used.

granted, this is mostly a cop-out, but I am struggling to understand what this block is trying to do, and it clearly has an off by one error in the indexing that causes lots of warnings like

In file included from /usr/include/c++/14/functional:65,
                 from /usr/include/dune/common/parallel/mpicommunication.hh:19,
                 from /usr/include/dune/common/parallel/mpihelper.hh:18,
                 from /build/opm/models/utils/start.hh:30,
                 from /build/examples/diffusion_pvs.cpp:30:
In member function 'constexpr const std::array<_Tp, _Nm>::value_type& std::array<_Tp, _Nm>::operator[](size_type) const [with _Tp = double; long unsigned int _Nm = 2]',
    inlined from 'constexpr const Dune::FieldVector<K, n>::value_type& Dune::FieldVector<K, n>::operator[](size_type) const [with K = double; int SIZE = 2]' at /usr/include/dune/common/fvector.hh:243:19,
    inlined from 'Opm::FvBasePrimaryVariables<TypeTag, VectorType>::Evaluation Opm::FvBasePrimaryVariables<TypeTag, VectorType>::makeEvaluation(unsigned int, unsigned int, Opm::LinearizationType) const [with TypeTag = Opm::Properties::TTag::DiffusionProblem; VectorType = Dune::FieldVector]' at /build/opm/models/discretization/common/fvbaseprimaryvariables.hh:120:27,
    inlined from 'void Opm::PvsIntensiveQuantities<TypeTag>::update(const ElementContext&, unsigned int, unsigned int) [with TypeTag = Opm::Properties::TTag::DiffusionProblem]' at /build/opm/models/pvs/pvsintensivequantities.hh:202:43:
/usr/include/c++/14/array:219:24: warning: array subscript 2 is above array bounds of 'std::__array_traits<double, 2>::_Type' {aka 'const double [2]'} [-Warray-bounds=]
  219 |         return _M_elems[__n];
      |                ~~~~~~~~^
/usr/include/c++/14/array: In member function 'void Opm::PvsIntensiveQuantities<TypeTag>::update(const ElementContext&, unsigned int, unsigned int) [with TypeTag = Opm::Properties::TTag::DiffusionProblem]':
/usr/include/c++/14/array:115:55: note: while referencing 'std::array<double, 2>::_M_elems'
  115 |       typename __array_traits<_Tp, _Nm>::_Type        _M_elems;

as the assert is never hit in any of the tests for this, I suggest this workaround unless somebody with a better understanding than me wants to fix it.

[akva2]

jenkins build this please