Update CI workflow

Author: i-am-sijia

.github/workflows/ci.yml

@@ -51,9 +51,11 @@ jobs:
       # as the pre-installed one is the latest release but not the most up-to-date
       - name: Install ActivitySim
         run: |
+          uv pip uninstall activitysim
           uv pip install --no-deps ./cloned/activitysim
 
       - name: Test this implementation
         run: |
-          uv run pytest ./test
+          source .venv/bin/activate
+          pytest ./test