fix docs building, see example on rtd docs

Author: skysomorphic

.readthedocs.yaml

@@ -11,11 +11,15 @@ build:
   tools:
     python: "3.13"
   jobs:
-    post_create_environment:
-      - pip install poetry
-      - poetry config virtualenvs.create false
     post_install:
-      - poetry install --with docs
+      # Install poetry
+      # https://python-poetry.org/docs/#installing-manually
+      - pip install poetry
+      # Install dependencies with 'docs' dependency group
+      # https://python-poetry.org/docs/managing-dependencies/#dependency-groups
+      # VIRTUAL_ENV needs to be set manually for now.
+      # See https://github.com/readthedocs/readthedocs.org/pull/11152/
+      - VIRTUAL_ENV=$READTHEDOCS_VIRTUALENV_PATH poetry install --with docs
 
 # Build documentation in the "docs/" directory with Sphinx
 sphinx: