Update the read-the-docs configuration yaml file.

Read-the-docs now requires explicit specification of the
sphinx configuration file (conf.py) in the .readthedocs.yaml file: https://about.readthedocs.com/blog/2024/12/deprecate-config-files-without-sphinx-or-mkdocs-config/

Also updating the Python version.

Author: zivy

.readthedocs.yaml

@@ -1,10 +1,13 @@
 version: 2
 formats: all
 
+sphinx:
+   configuration: docs/source/conf.py
+
 build:
   os: ubuntu-22.04
   tools:
-    python: "3.8"
+    python: "3.12"
 
 
 python: