optionally deterministic output files for F2PY
----------------------------------------------
``f2py`` now accepts the ``--empty-gen`` flag for producing all possible output
files, namely: ``modname-f2pywrappers.f``, ``modname-f2pywrappers2.f90``. This
allows writing generic output rules in ``cmake`` or ``meson`` and other build
systems. :ref:`f2py-meson` details usage.

Add release note for --empty-gen
MAINT: Add release note for --empty-gen
