Build failure with gcc14

[cqc-alec]

See e.g. https://github.com/CQCL/tket/actions/runs/18559574575/job/52905029299

Coming from Eigen:

In file included from /root/.conan2/p/eigenc00bf2f45d16d/p/include/eigen3/Eigen/Core:345,
                 from /root/.conan2/p/eigenc00bf2f45d16d/p/include/eigen3/Eigen/Dense:1,
                 from /root/.conan2/p/b/tket58b7e6e1601e3/b/include/tket/Utils/EigenConfig.hpp:33,
                 from /root/.conan2/p/b/tket58b7e6e1601e3/b/include/tket/Utils/MatrixAnalysis.hpp:21,
                 from /root/.conan2/p/b/tket58b7e6e1601e3/b/src/Utils/MatrixAnalysis.cpp:15:
In static member function ‘static void Eigen::internal::eigen_zero_impl<Xpr, true>::run(Xpr&) [with Xpr = Eigen::Map<Eigen::Matrix<int, -1, 1>, 0, Eigen::Stride<0, 0> >]’,
    inlined from ‘Derived& Eigen::DenseBase<Derived>::setZero() [with Derived = Eigen::Map<Eigen::Matrix<int, -1, 1>, 0, Eigen::Stride<0, 0> >]’ at /root/.conan2/p/eigenc00bf2f45d16d/p/include/eigen3/Eigen/src/Core/CwiseNullaryOp.h:553:42,
    inlined from ‘Eigen::SparseMatrix<Scalar_, Options_, StorageIndex_>& Eigen::SparseMatrix<Scalar_, Flags_, StorageIndex_>::operator=(const Eigen::SparseMatrixBase<OtherDerived>&) [with OtherDerived = Eigen::SparseMatrix<std::complex<double>, 1, int>; Scalar_ = std::complex<double>; int Options_ = 0; StorageIndex_ = int]’ at /root/.conan2/p/eigenc00bf2f45d16d/p/include/eigen3/Eigen/src/SparseCore/SparseMatrix.h:1548:73:
/root/.conan2/p/eigenc00bf2f45d16d/p/include/eigen3/Eigen/src/Core/Fill.h:128:11: error: ‘void* memset(void*, int, size_t)’ specified bound 18446744073709551612 exceeds maximum object size 9223372036854775807 [-Werror=stringop-overflow=]
  128 |     memset(dst_ptr, 0, num_bytes);
      |     ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

This prevents the release builds from completing.