Fix doc build

Author: Konstantin Ivaschenko

.readthedocs.yml

@@ -8,9 +8,14 @@ sphinx:
 # Optionally build your docs in additional formats such as PDF and ePub
 formats: all
 
-# Optionally set the version of Python and requirements required to build your docs
+# Set the OS, Python version and other tools you might need
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.7"
+
+# Python configuration
 python:
-  version: 3.7
   install:
     - method: pip
       path: .