pin version of setuptools instead of vsc-install

Author: lexming

.github/workflows/unittest.yml

@@ -48,8 +48,11 @@ jobs:
       - name: Install pytest
         run: python -m pip install pytest
 
+      - name: Install old setuptools
+        run: python -m pip install setuptools==59.8.0
+
       - name: Install vsc-install
-        run: python -m pip install vsc-install==0.21.4
+        run: python -m pip install vsc-install
 
       - name: Install build-tools
         run: python -m pip install .