Add build.tools to readthedocs config file

.readthedocs.yml

@@ -8,6 +8,8 @@ version: 2
 # Build environment
 build:
   os: ubuntu-22.04
+  tools:
+    python: "3.7"
 
 # Build documentation in the docs/ directory with Sphinx
 sphinx:
@@ -22,7 +24,6 @@ formats: all
 
 # Optionally set the version of Python and requirements required to build your docs
 python:
-  version: 3.7
   install:
     - requirements: docs/requirements.txt
     - method: setuptools