Update sphinx requirement from ~=7.4.0 to ~=7.4.3 in /fdmlpy

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@v7.4.0...v7.4.3)

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

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

fdmlpy/requirements.txt

@@ -1,3 +1,3 @@
 build~=0.10.0
-sphinx~=7.4.0
+sphinx~=7.4.3
 sphinx_rtd_theme~=2.0.0