Merge branch 'renovate/sphinx-4.x' into 'master'

Update dependency sphinx to v4.2.0

See merge request openappstack/openappstack!530

docs/requirements.txt

@@ -41,7 +41,7 @@ requests==2.26.0
     # via sphinx
 snowballstemmer==2.1.0
     # via sphinx
-sphinx==4.1.2
+sphinx==4.2.0
     # via
     #   -r requirements.in
     #   recommonmark