Try going back to the in-poetry install

.github/workflows/pipeline.yml

@@ -28,9 +28,9 @@ jobs: # jobs. We will have two jobs (test and publish) with multiple steps.
       - name: Install dependencies # install all dependencies
         run: |
           poetry config virtualenvs.create false --local
-          python -m pip install --upgrade pip wheel setuptools
+          poetry run python -m pip install --upgrade pip wheel setuptools
           # Because Poetry won't fix this https://github.com/python-poetry/poetry/issues/3433
-          # python -m pip install "sgmllib3k (==1.0.0)"
+          poetry run python -m pip install --no-use-pep517 sgmllib3k
           poetry install --all-extras
           pip install pytest pylint coverage mypy coveralls
       #   python -m nltk.downloader punkt stopwords