Issue with the "Setting up a Python Environment" doc

[mattt]

I found an issue with this document.

Title: Setting up a Python Environment
Location: https://fly.io/docs/python/the-basics/initial-setup/
Source: https://github.com/superfly/docs/blob/main/python/the-basics/initial-setup.html.md

Describe the issue

The guide for setting up a Python environment should mention uv as an option for dependency management.

Especially since its 0.3 release, uv has become a fully-fledged packaging tool. So beyond mentioning it as an alternative, I think it's worth considering updating the guide making uv the new default, replacing Poetry.

[mattt]

I opened a PR with these changes here: #1847