New packaging relying only pyproject.toml

.github/workflows/testing.yml

@@ -31,9 +31,6 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         python -m pip install -r dev-requirements.txt
-    - name: Install Windows dependencies
-      if: matrix.os == 'windows-latest'
-      run: python -m pip install -r win-requirements.txt
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names