Fix passing python version to updated tox

Author: piobeny

.github/workflows/main.yml

@@ -30,7 +30,7 @@ jobs:
       - name: Install tox
         run: pip install tox
       - name: Run tests
-        run: tox -e py${{ matrix.python }}
+        run: tox -e py${{ replace(matrix.python, '.', '') }}
       - name: Run linters
         run: tox -e pre-commit
       - name: Run type checking