Use lower version of markupsafe

Author: chfw

.github/workflows/pythonpackage.yml

@@ -18,6 +18,7 @@ jobs:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies
         run: |
+          pip install markupsafe==2.0.1        
           python -m pip install --upgrade pip setuptools
           pip install -r requirements.txt
       - name: Lint with flake8