Bump sphinx from 7.2.2 to 7.2.6

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 7.2.2 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@v7.2.2...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]>

doc/requirements.txt

@@ -1,7 +1,7 @@
 click==8.1.7
 entrypoints==0.4
 Pillow==10.0.0
-Sphinx==7.2.2
+Sphinx==7.2.6
 furo==2023.8.17
 ipython==8.14.0
 netCDF4==1.6.4