ModuleNotFoundError: No module named 'verifai' when running common20_1.scenic example

## Description

While running the `common20_1.scenic` example, Scenic fails with a `ModuleNotFoundError` for the `verifai` package.


scenic common20_1.scenic --simulate -p use2DMap True


<img width="1768" height="630" alt="Image" src="https://github.com/user-attachments/assets/d4a45dd2-6f8d-4390-bf8d-5ce181708f0c" />