Update sphinx to 8.1.2

[pyup-bot]

This PR updates sphinx from 8.1.0 to 8.1.2.

Changelog

8.1.2

=====================================

Bugs fixed
----------

* 13012: Expose :exc:`sphinx.errors.ExtensionError` in ``sphinx.util``
for backwards compatibility.
This will be removed in Sphinx 9, as exposing the exception
in ``sphinx.util`` was never intentional.
:exc:`!ExtensionError` has been part of ``sphinx.errors`` since Sphinx 0.9.
Patch by Adam Turner.

8.1.1

=====================================

Bugs fixed
----------

* 13006: Use the preferred https://www.cve.org/ URL for
the :rst:role:`:cve: <cve>` role.
Patch by Hugo van Kemenade.
* 13007: LaTeX: Improve resiliency when the required
``fontawesome`` or ``fontawesome5`` packages are not installed.
Patch by Jean-François B.

Links

• PyPI: https://pypi.org/project/sphinx
• Changelog: https://data.safetycli.com/changelogs/sphinx/