Context

Describe the background behind the problem.

PyMongo's test workflow repeats the same uv/just installation and dependency-install steps across most of its CI jobs, with no way to share that logic with other MongoDB driver repos. drivers-github-tools already hosts reusable CI building blocks for other drivers, but nothing equivalent exists for Python's uv/just tooling. A follow-up ticket will cover rolling the new action out to other Python team repos once it lands here.

Design: https://gist.github.com/blink1073/d1621c6d0f08765be66185b3bb9c9c60

Definition of done

What must be done to consider the task complete?

A new shared action exists in mongodb-labs/drivers-github-tools that installs uv and just, and can optionally install project dependencies when supported. mongo-python-driver's CI workflow is updated to consume it in place of the duplicated steps, with no change in test behavior or coverage.  We should use setup-python with the desired python-version and let uv use that python version: https://github.com/astral-sh/setup-uv#do-i-still-need-actionssetup-python-alongside-setup-uv.

Pitfalls

What should the implementer watch out for? What are the risks?

• Not every CI job needs the dependency-install step, so it must be skippable rather than forced.
• The action needs to stay generic enough for other python driver repos to adopt, not just PyMongo.
• Third-party action versions/pins must follow this repo's existing security/ref-pinning policy.