build(deps): bump sphinxemoji from 0.2.0 to 0.3.1 in /requirements (#146)

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Diff for: requirements/requirements_doc.txt

@@ -19,4 +19,4 @@ sphinx-gallery==0.15.0
 sphinx-autobuild==2021.3.14
 sphinx-autodoc-typehints==1.25.2
 sphinx-notfound-page==1.0.0
-sphinxemoji==0.2.0
+sphinxemoji==0.3.1