chore(poetry-multistage, Dockerfile): remove redundant line

see https://github.com/python-poetry/poetry/pull/9542/files/93540ebb88fd2bcb34bf11b2707372577969e57f#r1991984936

Co-authored-by: Janne Holopainen <[email protected]>

Author: gianfa

docker-examples/poetry-multistage/Dockerfile

@@ -8,7 +8,7 @@ ENV POETRY_VIRTUALENVS_IN_PROJECT=1
 ENV POETRY_VIRTUALENVS_CREATE=1
 ENV PYTHONDONTWRITEBYTECODE=1
 ENV PYTHONUNBUFFERED=1
-# Tell Poetry where to place its cache and virtual environment
+# Tell Poetry where to place its cache
 ENV POETRY_CACHE_DIR=/opt/.cache
 
 RUN pip install "poetry==${POETRY_VERSION}"