fix readthedocs with poetry

xref readthedocs/readthedocs.org#11152

Author: gjoseph92

.readthedocs.yml

@@ -13,9 +13,7 @@ build:
       # Install poetry
       # https://python-poetry.org/docs/#installing-manually
       - pip install poetry
-      # Tell poetry to not use a virtual environment
-      - poetry config virtualenvs.create false
     post_install:
       # Install dependencies with 'docs' dependency group
       # https://python-poetry.org/docs/managing-dependencies/#dependency-groups
-      - poetry install --only main,docs
+      - VIRTUAL_ENV=$READTHEDOCS_VIRTUALENV_PATH poetry install --only main,docs