Downgrade setuptools to fix CI

.github/workflows/ci.yaml

@@ -56,7 +56,7 @@ jobs:
         run: |
           python -m venv venv
           . venv/bin/activate
-          pip install -U "pip<20.3" setuptools
+          pip install -U "pip<20.3" "setuptools<56.2"
           pip install -r requirements.txt -r requirements_test.txt
       - name: Generate partial pre-commit restore key
         id: generate-pre-commit-key
@@ -580,7 +580,7 @@ jobs:
 
           python -m venv venv
           . venv/bin/activate
-          pip install -U "pip<20.3" setuptools wheel
+          pip install -U "pip<20.3" "setuptools<56.2" wheel
           pip install -r requirements_all.txt
           pip install -r requirements_test.txt
           pip install -e .