pip install setuptools in an additional place

(missing from the last commit)

setuptools is no longer pre-installed in Python 3.12 virtual
environments.
https://docs.python.org/3.12/whatsnew/3.12.html
python/cpython#95299

.github/workflows/packages.yml

@@ -70,7 +70,7 @@ jobs:
         python-version: ${{ matrix.python-version }}
 
     - name: Dependencies
-      run: python -m pip install --upgrade pip wheel
+      run: python -m pip install --upgrade pip setuptools wheel
 
     - name: Build
       run: python setup.py bdist_wheel