requirements: update sphinx requirement from <4.2.1 to <8.1.2

[dependabot]

Updates the requirements on sphinx to permit the latest version.

Release notes

Sourced from sphinx's releases.

Sphinx 8.1.1

Changelog: https://www.sphinx-doc.org/en/master/changes.html

Bugs fixed

• #13006: Use the preferred https://www.cve.org/ URL for the :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.

Changelog

Sourced from sphinx's changelog.

Release 8.1.1 (in development)

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.

Release 8.1.0 (released Oct 10, 2024)

Dependencies

• #12756: Add lower-bounds to the sphinxcontrib-* dependencies. Patch by Adam Turner.
• #12833: Update the LaTeX parskip package from 2001 to 2018. Patch by Jean-François B.

Incompatible changes

• #12763: Remove unused internal class sphinx.util.Tee. Patch by Adam Turner.
• #12822: LaTeX: for Unicode engines, the :ref:fvset default is changed to '\\fvset{fontsize=auto}' from '\\fvset{fontsize=\\small}'. Code-blocks are unchanged as FreeMono is now loaded with Scale=0.9. An adjustment to existing projects is needed only if they used a custom :ref:fontpkg configuration and did not set :ref:fvset. Patch by Jean-François B.
• #12875: Disable smartquotes for languages: zh_CN and zh_TW by default. Patch by A. Rafey Khan.

Deprecated

• #12762: Deprecate sphinx.util.import_object. Use :py:func:importlib.import_module instead. Patch by Adam Turner.
• #12766: Deprecate sphinx.util.FilenameUniqDict and sphinx.util.DownloadFiles. Patch by Adam Turner.

Features added

... (truncated)

Commits

• 61d8885 Bump to 8.1.1 final
• 35e6d7a Include the issue number in CHANGES
• 61d6e40 LaTeX: Improve resiliency when fontawesome is not not installed (#13009)
• c23697a Use method colour key in the Builder API graph (#12998)
• 5fa06f6 Note the new CVE base URL in CHANGES
• ca99447 Move CVE and CWE base URLs to class constants
• 58263e2 Update CVE URL (#13006)
• 2e54d4e Bump version
• 2f1d775 Bump to 8.1.0 final
• 668bb03 Partially revert "Update message catalogues (#12770)"
• Additional commits viewable in compare view

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[dependabot]

Superseded by #3069.