chore: Update ReadTheDocs config file to be compliant

* c.f. https://twitter.com/readthedocs/status/1522266722635436041
* scikit-hep/pyhf#2267

.readthedocs.yml

@@ -5,17 +5,25 @@
 # Required
 version: 2
 
+# Set the version of Python and other tools you might need
+build:
+  os: ubuntu-22.04
+  tools:
+    python: "3.11"
+  apt_packages:
+    - curl
+    - jq
+
 # Build documentation in the docs/ directory with Sphinx
 sphinx:
   configuration: docs/conf.py
 
-# Optionally build your docs in additional formats such as PDF
+# If using Sphinx, optionally build your docs in additional formats such as PDF and ePub
 formats:
   - pdf
 
-# Optionally set the version of Python and requirements required to build your docs
+# python -m pip install '.[docs,contrib]'
 python:
-  version: 3.8
   install:
     - method: pip
       path: .