Update CI configuration to install dependencies with system site packages

Author: rpobotin

.github/workflows/pytest.yml

@@ -20,9 +20,8 @@ jobs:
         run: |
           curl -LsSf https://astral.sh/uv/install.sh | sh
           python -m pip install --upgrade pip
-          uv venv
           pip install flake8 pytest
-          if [ -f requirements.txt ]; then uv pip install -r requirements.txt --upgrade; fi
+          if [ -f requirements.txt ]; then uv pip install -r requirements.txt --upgrade --system; fi
       - name: Install browsers
         run: python -m playwright install
       - name: Test with pytest