Merge pull request #1565 from Bastian-Krause/bst/rtd-2024

readthedocs: set explicit sphinx configuration and bump Ubuntu/Python

Author: Emantor

.readthedocs.yaml

@@ -1,5 +1,8 @@
 version: 2
 
+sphinx:
+  configuration: doc/conf.py
+
 python:
   install:
     - method: pip
@@ -8,6 +11,6 @@ python:
         - doc
 
 build:
-  os: "ubuntu-22.04"
+  os: "ubuntu-24.04"
   tools:
-    python: "3.11"
+    python: "3.13"