Build fails with Python 3.13

Attempting to build ligo-segments against Python 3.13 on macOS (clang 17) produces the following errors:

  Running command Building wheel for ligo-segments (pyproject.toml)
  src/segmentlist.c:249:21: error: call to undeclared function '_PyList_Extend'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    249 |         PyObject *result = _PyList_Extend(l, v);
        |                            ^
  src/segmentlist.c:249:21: note: did you mean 'PyList_Extend'?
  /Users/runner/miniforge3/conda-bld/ligo-segments_1725300874558/_h_env/include/python3.13/cpython/listobject.h:52:17: note: 'PyList_Extend' declared here
     52 | PyAPI_FUNC(int) PyList_Extend(PyObject *self, PyObject *iterable);
        |                 ^
  src/segmentlist.c:249:12: error: incompatible integer to pointer conversion initializing 'PyObject *' (aka 'struct _object *') with an expression of type 'int' [-Wint-conversion]
    249 |         PyObject *result = _PyList_Extend(l, v);
        |                   ^        ~~~~~~~~~~~~~~~~~~~~
  2 errors generated.
  error: command '/Users/runner/miniforge3/conda-bld/ligo-segments_1725300874558/_build_env/bin/x86_64-apple-darwin13.4.0-clang' failed with exit code 1