Bump sphinx from 4.3.2 to 7.1.0 (#967)

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 4.3.2 to 7.1.0.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES)
- [Commits](sphinx-doc/sphinx@v4.3.2...v7.1.0)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
(cherry picked from commit eeb141a)

doc/requirements.txt

@@ -1,3 +1,3 @@
-sphinx==4.3.2
+sphinx==7.1.0
 sphinx_rtd_theme==1.2.2
 readthedocs-sphinx-search==0.3.1