Upgrade Python dependencies

Allows for docs to be built on Python3.9

Makefile

@@ -227,8 +227,8 @@ test:
 
 .installed.cfg: requirements.txt buildout.cfg
 	./bin/pip install -r requirements.txt
-	./bin/pip install --upgrade pip==19.2.1
-	./bin/pip install --upgrade setuptools==41.0.1
+	./bin/pip install --upgrade pip==22.0.3
+	./bin/pip install --upgrade setuptools==51.3.3
 	./bin/buildout -v
 
 docsdev: ./bin/activate .installed.cfg

requirements.txt

@@ -1 +1 @@
-zc.buildout==2.13.2
+zc.buildout==2.13.6