Log Message:
py-sphinxcontrib-bibtex: updated to 2.6.3

2.6.3 (12 September 2024)

* Add setuptools as a runtime dependency on Python 3.12. This works around
  an issue with the latest release of pybtex not working on Python 3.12
  otherwise.

* Migrate setup.py to pyproject.toml. This fixes a ``namespace_packages``
  warning on setuptools.