CI: Use build frontend in deploy step

Author: ghisvail

.github/workflows/pythonpackage.yml

@@ -91,9 +91,9 @@ jobs:
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install build tools
-      run: python -m pip install --upgrade pip setuptools wheel twine
+      run: python -m pip install build twine
     - name: Build source and wheel distributions
-      run: python setup.py sdist bdist_wheel
+      run: python -m build
     - name: Check distributions
       run: twine check dist/*
     - uses: actions/upload-artifact@v2