The version of sphinx we are pinned to is not compatible with Python 3.13

[rgacogne]

• Program: Authoritative, Recursor, dnsdist
• Issue type: Bug report

Short description

The version of sphinx we are pinned to is not compatible with Python 3.13 which means it's no longer possible to build our documentation on Arch (for example, more distributions to come).

Fixing that would mean making https://github.com/PowerDNS/sphinx-jsondomain/ https://github.com/PowerDNS/sphinx-lua and https://github.com/PowerDNS/sphinxcontrib-openapi compatible with recent versions of Sphinx, and moving away from these extensions.

[rgacogne]

For the openapi one it seems that https://github.com/sphinx-contrib/openapi is up to date.