Bump sphinxemoji from 0.2.0 to 0.3.1 in /requirements

Bumps [sphinxemoji](https://github.com/sphinx-contrib/emojicodes) from 0.2.0 to 0.3.1.
- [Commits](sphinx-contrib/emojicodes@v0.2.0...v0.3.1)

---
updated-dependencies:
- dependency-name: sphinxemoji
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

requirements/requirements_doc.txt

@@ -24,6 +24,6 @@ sphinx-autobuild==2021.3.14
 sphinx-autodoc-typehints==1.25.2
 sphinxcontrib-websupport==1.2.7
 sphinx-copybutton==0.5.2
-sphinxemoji==0.2.0
+sphinxemoji==0.3.1
 sphinx-gallery==0.15.0
 sphinx-notfound-page==1.0.0