delaunayn simplex check consistency and performance improvement (bug #60818) * delaunayn.m: Apply consistent volume calculation across all trivial simplex removal code paths. Vectorize 3D simplex removal code path and minimize function calls within >3D loop for performance improvement. Update FIXME note for future performance improvement. Add input type validation checks. Add BISTs for dimensions other than 2D, simplex removal, and input validation. * etc/News.8.md: Describe function improvements under General Improvements.

#include <octave/oct.h>

DEFUN_DLD (addtwomatrices, args, , "Add A to B")
{
  if (args.length () != 2)
    print_usage ();

  NDArray A = args(0).array_value ();
  NDArray B = args(1).array_value ();

  return octave_value (A + B);
}