ci: Windows isn't finding pytest, try refreshing its cache

Author: tomtseng

.circleci/config.yml

@@ -170,7 +170,7 @@ commands:
       - save_cache:
           paths:
             - .\venv
-          key: v11win-dependencies-{{ checksum "setup.py" }}-{{ checksum "ci/build_and_activate_venv.ps1" }}
+          key: v12win-dependencies-{{ checksum "setup.py" }}-{{ checksum "ci/build_and_activate_venv.ps1" }}
 
       - run:
           name: install imitation