use python 3.9 in rtd docs builds

hoefling · hoefling · commit 87fb5aa6aae0 · 2022-08-20T20:50:12.000+02:00
Signed-off-by: oleg.hoefling &lt;oleg.hoefling@gmail.com&gt;
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
@@ -1,10 +1,14 @@
 version: 2
 
+build:
+  os: ubuntu-20.04
+  tools:
+    python: '3.9'
+
 sphinx:
   configuration: doc/source/conf.py
 
 python:
-  version: 3.8
   install:
     - method: pip
       path: .
