[python] move to pybind11 2.12.0

dune/python/pybind11/CMakeLists.txt

dune/python/pybind11/LICENSE

dune/python/pybind11/_version.py

dune/python/pybind11/attr.h

dune/python/pybind11/buffer_info.h

dune/python/pybind11/cast.h

dune/python/pybind11/detail/class.h

dune/python/pybind11/detail/common.h

dune/python/pybind11/detail/descr.h

dune/python/pybind11/detail/init.h

dune/python/pybind11/detail/internals.h

dune/python/pybind11/detail/type_caster_base.h

dune/python/pybind11/eigen/CMakeLists.txt

dune/python/pybind11/eigen/common.h

dune/python/pybind11/eigen/matrix.h

dune/python/pybind11/eigen/tensor.h

dune/python/pybind11/embed.h

dune/python/pybind11/functional.h

dune/python/pybind11/gil.h

dune/python/pybind11/gil_safe_call_once.h