There is an updated pull request by ahesford against master on the void-packages repository

https://github.com/ahesford/void-packages pybind11
https://github.com/void-linux/void-packages/pull/20218

New packages: python3-breathe and python3-pybind11
Pybind11 is a C++ header-only library that facilitates creation of Python bindings for C++ libraries. The man page for pybind11 is generated using the python3-breathe doxygen bridge.

A patch file from https://github.com/void-linux/void-packages/pull/20218.patch is attached