Proposed new feature or change:

#20881 highlighted and #20884 elaborated on the fact that due to historical reasons, there is some duplication within the NumPy-C and F2PY generated C code.

These should be reduced for maximally efficient maintainable code. For over a decade now, F2PY is distributed with NumPy and so this issue stipulates that instead of Python.h and typedef structures in F2PY, we should instead depend explicitly on <numpy/npy_common.h> as discussed here.