Update sphinx requirement from <7.3 to <7.4

Updates the requirements on [sphinx](https://github.com/sphinx-doc/sphinx) to permit the latest version.
- [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...v7.3.7)

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

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

dev-requirements.txt

@@ -3,7 +3,7 @@ pytest
 pytest-cov
 coverage
 mock
-sphinx<7.3
+sphinx<7.4
 sphinx_rtd_theme
 jinja2
 pytz