PR build's virtualenv caching does not handle file dependencies like `../../packages/service` correctly

[bkeryan]

Tech Debt

The PR build uses actions/cache to cache virtualenvs based on the hash of poetry.lock. For external dependencies, this works great, but when using file dependencies to reference other packages in the same repo such as ../../packages/service, this doesn't work right because the contents of ../../packages/service are not reflected in the hash of poetry.lock.

Workarounds:

• Use develop = true to avoid copying local packages to the venv
• Modify poetry.lock when making changes to code
• Use the GitHub Actions tab to delete the cache.

AB#2867348