Bump sphinx from 7.2.5 to 7.2.6 in /docs

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 7.2.5 to 7.2.6.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v7.2.5...v7.2.6)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

docs/requirements.txt

@@ -1,5 +1,5 @@
 furo==2023.9.10
-sphinx==7.2.5
+sphinx==7.2.6
 sphinx-click==5.0.1
 sphinx-copybutton==0.5.2
 # myst-nb==0.17.2