Bump the actions group with 1 update

Updates the requirements on [sphinx](https://github.com/sphinx-doc/sphinx) to permit the latest version.

Updates `sphinx` 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@v0.1.61611...v7.2.6)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:development
  dependency-group: actions
...

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

setup.cfg

@@ -52,7 +52,7 @@ test =
     pytest-remotedata
     ci-watson
 docs =
-    sphinx<7
+    sphinx<8
     sphinx-automodapi
     sphinx-rtd-theme