Update to use pybind11 2.9.1 (Feb 2, 2022)

[zwimer]

This improvement would update binder / the pybind11 fork in lockstep to be more inline with pybind/pybind11's master branch. Currently binder only works with the RosettaCommons for of pybind11, which is now over a year old and is lacking some key features such as:

Allow Python builtins to be used as callbacks in CPython. #1413 enum: add missing Enum.value property. #2739 Allow thread termination to be avoided during shutdown for CPython 3.7+ via .disarm for gil_scoped_acquire/gil_scoped_release. #2657 Support PyPy 7.3.7 and the PyPy3.8 beta. Test python-3.11 on PRs with the python dev label. #3419

Among quite a few bux fixes and, including a few memory error bug fixes. Importantly there is additional support for newer python interpreters (PyPy versions) which would be useful for projects which care about performance, on key benefit of pybind11.

If Python2 support is desired, Version 2.9.0 (Dec 28, 2021) still supports 2.7 bindings and is fairly modern and supports all the features listed above

[lyskov]

Thank you for heads up and change list @zwimer ! This is certainly needed and it is in my list so i will take of it as soon as time permit.