Adding pyproject.toml and using ruff to format the code

.github/workflows/python-app.yml

@@ -22,11 +22,11 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install ruff pytest pytest-cov
+          pip install ruff pytest pytest-cov pytest-xdist
           pip install .
       - name: Lint with ruff
         run: |
           ruff check
       - name: Test with pytest
         run: |
-          pytest --cov
+          pytest -n 4 --cov