Update main.yml

.github/workflows/main.yml

@@ -19,7 +19,7 @@ jobs:
             -   name: Install dependencies
                 run: |
                     python -m pip install --upgrade pip
-                    pip install tox tox-gh-actions wheel
+                    pip install tox tox-gh-actions setuptools wheel
             -   name: Test with tox
                 run: tox
             -   name: Build distributions