Merge branch 'valls-patch-7' into 'master'

Update sphinx version which fix MarkupSafe failing constraint

See merge request !3731

requirements-doc.txt

 # Conda requirement file 
 # Documentation requirements
-sphinx<4.0.0  # sphinx release is not yet stable
+sphinx>=4.0.2
 graphviz
 pygments
 markdown-inline-graphviz