Fix RTD config

.readthedocs.yml → .readthedocs.yaml

@@ -2,19 +2,19 @@
 # See https://docs.readthedocs.io/en/stable/config-file/v2.html for details
 version: 2
 
+build:
+  os: ubuntu-22.04
+  apt_packages:
+    - graphviz
+  tools:
+    python: "3.11"
+
 sphinx:
   builder: html
   configuration: docs/conf.py
   fail_on_warning: true
 
-# Set the version of Python and requirements required to build your docs
-build:
-  os: ubuntu-22.04
-  tools:
-    python: "3.10"
-
 python:
-  system_packages: false
   install:
     - method: pip
       path: .