hotfix for requirementslib dependencies

see sarugaku/requirementslib#296

.github/workflows/release_pypi.yml

@@ -56,7 +56,7 @@ jobs:
         - name: Install build dependencies
           run: |
             python -m pip install --upgrade pip
-            pip install --upgrade setuptools wheel twine pipenv-setup
+            pip install --upgrade setuptools wheel twine pipenv-setup chardet
         - name: Update setup.py according to Pipfile
           run: pipenv-setup sync
         - name: Build package