Updated to latest Sphinx version

Makefile

@@ -227,7 +227,7 @@ test:
 
 .installed.cfg: requirements.txt buildout.cfg
 	./bin/pip install -r requirements.txt
-	./bin/pip install --upgrade pip==22.0.3
+	./bin/pip install --upgrade pip==21.3.1
 	./bin/pip install --upgrade setuptools==51.3.3
 	./bin/buildout -v
 

buildout.cfg

@@ -11,5 +11,5 @@ eggs =
     sphinx-bootstrap-theme
 
 [versions]
-Sphinx = 2.1.2
-docutils = 0.15.2
+Sphinx = 4.5.0
+docutils = 0.17.1