Fix build read the docs. 7th attempt

Author: Smurf2-pluto

.readthedocs.yaml

@@ -4,10 +4,13 @@
 version: 2
 
 build:
-  os: ubuntu-22.04
-  python:
-    version: 3.12
-    install:
-      - requirements: docs/_ext/djangodummy/requirements.txt
+  os: ubuntu-20.04
+  tools:
+    python: "3.8"
+
 sphinx:
   configuration: docs/conf.py
+
+python:
+  install:
+    - requirements: docs/_ext/djangodummy/requirements.txt