workarounding pyvinecopulib setuptools build-time dependency conflict (#1324)

Author: slayoo

.github/workflows/tests+artifacts+pypi.yml

@@ -198,6 +198,11 @@ jobs:
       - if: steps.cache.outputs.cache-hit != 'true'
         run: |
           python -m pip uninstall -y jupyterlab-server # https://github.com/pypa/pip/issues/6275
+          
+          python -m pip install "setuptools==64.0.0"
+          python -m pip install pyvinecopulib # requires newer setuptools
+          python -m pip install "setuptools==56.0.0"
+          
           python -m pip install -e . -e ./examples
           python -m pip install -r tests/devops_tests/requirements.txt
       - if: steps.cache.outputs.cache-hit != 'true'