fixup! Revert libxml2 and libxslt installation

Author: cclauss

.github/workflows/build.yml

@@ -20,9 +20,6 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip setuptools six wheel
-          # sudo apt-get install libxml2 libxslt
-          sudo snap install libxml2 libxslt
-          python -m pip install matplotlib>=3.4.2
           python -m pip install mypy pytest-cov -r requirements.txt
       - run: mypy --install-types --non-interactive .
       - name: Run tests