Update pytest-docs.yml

Author: tschaume

.github/workflows/pytest-docs.yml

@@ -33,7 +33,7 @@ jobs:
         run: sudo apt-get update && sudo apt-get install chromium-chromedriver
       - name: Install dependencies
         run: |
-          python${{ matrix.python-version }} -m pip install --upgrade pip packaging wheel
+          python${{ matrix.python-version }} -m pip install --upgrade pip packaging wheel cython setuptools
           python${{ matrix.python-version }} -m pip install `grep numpy== requirements/ubuntu-latest_py${{ matrix.python-version }}_extras.txt`
           python${{ matrix.python-version }} -m pip install -r requirements/ubuntu-latest_py${{ matrix.python-version }}_extras.txt
           python${{ matrix.python-version }} -m pip install --upgrade pip