Bump sphinx from 2.4.2 to 2.4.3

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 2.4.2 to 2.4.3.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/3.x/CHANGES)
- [Commits](sphinx-doc/sphinx@v2.4.2...v2.4.3)

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

setup.py

@@ -27,7 +27,7 @@
         "flake8-bugbear==20.1.4",
         "pre-commit>=1.20,<3.0",
     ],
-    "docs": ["Sphinx==2.4.2", "sphinx-issues==1.2.0", "sphinx-typlog-theme==0.8.0"]
+    "docs": ["Sphinx==2.4.3", "sphinx-issues==1.2.0", "sphinx-typlog-theme==0.8.0"]
     + FRAMEWORKS,
 }
 EXTRAS_REQUIRE["dev"] = EXTRAS_REQUIRE["tests"] + EXTRAS_REQUIRE["lint"] + ["tox"]