Bump sphinxcontrib-htmlhelp from 2.0.1 to 2.0.3 in /extra_requirements

Bumps [sphinxcontrib-htmlhelp](https://github.com/sphinx-doc/sphinxcontrib-htmlhelp) from 2.0.1 to 2.0.3.
- [Release notes](https://github.com/sphinx-doc/sphinxcontrib-htmlhelp/releases)
- [Changelog](https://github.com/sphinx-doc/sphinxcontrib-htmlhelp/blob/master/CHANGES)
- [Commits](sphinx-doc/sphinxcontrib-htmlhelp@2.0.1...2.0.3)

---
updated-dependencies:
- dependency-name: sphinxcontrib-htmlhelp
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

extra_requirements/requirements-docs.txt

@@ -12,7 +12,7 @@ sphinx_rtd_theme==1.0.0
 sphinx==4.4.0
 sphinxcontrib_applehelp==1.0.2
 sphinxcontrib_devhelp==1.0.2
-sphinxcontrib_htmlhelp==2.0.1
+sphinxcontrib_htmlhelp==2.0.3
 sphinxcontrib_jsmath==1.0.1
 sphinxcontrib_qthelp==1.0.3
 typing-extensions==4.1.1