Upgrade pip, as the tests now practically depend on pip >= 25.1

Author: stefanor

.github/workflows/ci.yaml

@@ -417,6 +417,8 @@ jobs:
       env:
         CIBW_BUILD: ${{ matrix.spec }}
         CIBW_PRERELEASE_PYTHONS: 'True'
+        # Temporary, until virtualenv has pip >= 25.1 by default
+        CIBW_DEPENDENCY_VERSIONS: 'latest'
         CIBW_TEST_REQUIRES: pytest setuptools
         CIBW_TEST_COMMAND: pip install pip --upgrade; cd {project}; PYTHONUNBUFFERED=1 pytest
         MACOSX_DEPLOYMENT_TARGET: ${{ matrix.deployment_target || '10.9' }}

testing/cffi0/test_zintegration.py

@@ -32,6 +32,7 @@ def create_venv(name):
                 '-m',
                 'pip',
                 'install',
+                'pip',
                 'setuptools',
                 '--upgrade'
             ])