Update sphinx requirement from <5.4 to <7.3

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)
- [Commits](sphinx-doc/sphinx@v0.1.61611...v7.2.2)

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

Signed-off-by: dependabot[bot] <support@github.com>

requirements_dev.txt

@@ -6,7 +6,7 @@ flake8<7.0
 isort
 pylint
 pytest
-Sphinx<5.4
+Sphinx<7.3
 sphinxcontrib-applehelp
 sphinxcontrib-devhelp
 sphinxcontrib-htmlhelp