Update Python and Sphinx versions for docs (#1567)

Author: hugovk

.readthedocs.yaml

@@ -6,7 +6,7 @@ version: 2
 build:
   os: ubuntu-22.04
   tools:
-    python: "3.11"
+    python: "3"
 
 sphinx:
   configuration: docs/conf.py

docs/requirements.txt

@@ -3,7 +3,7 @@
 # Sphinx version is pinned so that new versions that introduce new warnings
 # won't suddenly cause build failures. Updating the version is fine as long
 # as no warnings are raised by doing so.
-sphinx==4.2.0
+sphinx==7.2.6
 
 # The theme used by the documentation is stored separately, so we need
 # to install that as well.