post-nanobind migration TODOs

[slayoo]

• check the leak messages
• bring back the self-contained headers checks in CMakeLists.txt -> reinstantiate header independence check in CMakeLists.txt (was commented out in the nanobind PR) #437
• revisit issues/PRs that likely are now solved/possible/obsolete:
  • bump pibind11 #414
  • phase out setup.py in favour of pyproject.toml #403
  • CAMP-enabled object initialisation (incl. new multiphase chemistry example notebook depicting CAMP-enabled simulation) #368,
  • exception propagation seems not to work on arm64 (failing test_spec_by_name_not_found test on CI) #348,
  • introduce new Matlab compatibility workaround proposed in pybind11 #334,
  • multi-mode dist modes are returned back in reverse order wrt the ctor input #213
  • lack of hyperlinks from type names in docs (since introduction of the _PyPartMC module "hack" for Windows & Python >=3.8); also some function signatures have arg0, arg1 with no types #99
  • pdoc html is missing docstrings for properties (while it works for methods) #413

[slayoo]

• the PyPI upload did occur, but version id is wrong: https://pypi.org/project/PyPartMC/0.0.0/

symptoms as here: pypa/setuptools-scm#636

being addressed here: #436

[slayoo]

• pdoc needs fixing - the only thing from the API that is now picked is the si namedtuple

[slayoo]

the shift to nanobind indeed helped with the multiple-ctr issues in the CAMP PR, kudos @Griger5!

[slayoo]

closing this one, as any remaining TODOs have their own open issue - all what has been solved by nanobind migration from the above list has been closed