Hardcopy of pybind11 instead of using git submodules (#552)

* removed pybind as submodule
* added hardcopy of pybind11 2.10.0
* rename pybind11 folder to avoid conflicts when changing branch

Co-authored-by: Dhanya Thattil <dhanya.thattil@psi.ch>

libs/pybind/setup.cfg

@@ -0,0 +1,50 @@
+[metadata]
+long_description = file: README.rst
+long_description_content_type = text/x-rst
+description = Seamless operability between C++11 and Python
+author = Wenzel Jakob
+author_email = wenzel.jakob@epfl.ch
+url = https://github.com/pybind/pybind11
+license = BSD
+
+classifiers =
+    Development Status :: 5 - Production/Stable
+    Intended Audience :: Developers
+    Topic :: Software Development :: Libraries :: Python Modules
+    Topic :: Utilities
+    Programming Language :: C++
+    Programming Language :: Python :: 3 :: Only
+    Programming Language :: Python :: 3.6
+    Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3.8
+    Programming Language :: Python :: 3.9
+    Programming Language :: Python :: 3.10
+    Programming Language :: Python :: 3.11
+    License :: OSI Approved :: BSD License
+    Programming Language :: Python :: Implementation :: PyPy
+    Programming Language :: Python :: Implementation :: CPython
+    Programming Language :: C++
+    Topic :: Software Development :: Libraries :: Python Modules
+
+keywords =
+    C++11
+    Python bindings
+
+project_urls =
+    Documentation = https://pybind11.readthedocs.io/
+    Bug Tracker = https://github.com/pybind/pybind11/issues
+    Discussions = https://github.com/pybind/pybind11/discussions
+    Changelog = https://pybind11.readthedocs.io/en/latest/changelog.html
+    Chat = https://gitter.im/pybind/Lobby
+
+[options]
+python_requires = >=3.6
+zip_safe = False
+
+
+[flake8]
+max-line-length = 120
+show_source = True
+exclude = .git, __pycache__, build, dist, docs, tools, venv
+extend-ignore = E203, E722, B950
+extend-select = B9