Same for cffi

.github/workflows/tests.yml

@@ -110,6 +110,7 @@ jobs:
           pip install -U setuptools wheel twine build
           pip install -U 'cython>=3.0.10'
           pip install -U coverage
+          pip install -U cffi
           pip install -U persistent zope.interface zope.proxy
       - name: Install perfmetrics (non-Mac)
         if: ${{ ! startsWith(runner.os, 'Mac') }}