Log Message:
py-pybind11: updated to 2.8.1

v2.8.1 (Oct 27, 2021)

Changes and additions:

The simple namespace creation shortcut added in 2.8.0 was deprecated due to \ 
usage of CPython internal API, and will be removed soon. Use \ 
py::module_::import("types").attr("SimpleNamespace").
Add C++ Exception type to throw and catch AttributeError. Useful for defining \ 
custom __setattr__ and __getattr__ methods.

Fixes:

Fixed the potential for dangling references when using properties with \ 
std::optional types.
Modernize usage of PyCodeObject on Python 3.9+ (moving toward support for Python \ 
3.11a1)
A long-standing bug in eigen.h was fixed. The bug was unmasked by newly added \ 
static_assert's in the Eigen 3.4.0 release.
Support multiple raw inc…