Newer RTD theme versions have dropped support for the ancient sphinx version pinned by default, so no need to override

Author: dvdoug

.readthedocs.yaml

@@ -7,7 +7,7 @@ version: 2
 
 # Set the version of Python and other tools you might need
 build:
-  os: ubuntu-20.04
+  os: ubuntu-22.04
   tools:
     python: "3"
     # You can also specify other tool versions:

docs/requirements.txt

@@ -1,3 +1,2 @@
-# RTD pins these by default to ancient versions
-sphinx ~= 6.2
+# RTD pins by default to ancient versions
 sphinx-rtd-theme ~= 1.2