Update RTD for pixi

Author: VeckoTheGecko

.readthedocs.yaml

@@ -6,6 +6,9 @@ sphinx:
 
 build:
   os: ubuntu-lts-latest
+  tools:
+    # just so RTD stops complaining
+    python: "latest"
   jobs:
     create_environment:
       - asdf plugin add pixi
@@ -18,6 +21,9 @@ build:
       - git update-index --assume-unchanged doc/conf.py ci/requirements/doc.yml
     install:
       - pixi install -e doc
+    build:
+      html:
+        - BUILDDIR=$READTHEDOCS_OUTPUT pixi run -e doc make html
 
 formats:
   - htmlzip