python: make PET default locator

[isabelizimm]

Changes from "js" locator to the PET. 🎉

This PR also removes CI runs for upstream smoke tests. This was brought on due to the fact that smoke tests do not run from the expected positron/extensions/positron-python directory, so the pet binary would need to be redownloaded and inserted into the temporary testing path. We have disabled all behavior that is being tested in the smoke tests besides: checking if the LSP is on, running a Python file in the terminal, and checking if Smart Send is on. These are all features that are covered in Positron's own e2e tests. Since the smoke tests are not adding additional coverage or information to our testing suite, we decided to remove them completely.

Release Notes

New Features

• python: consider making PET default interpreter locator #6582 Use Rust-based Python Environment Tools locator as default.

Bug Fixes

• N/A

QA Notes

passes CI and if you poke around in different workspaces, Python should be discovered. I don't think we need to add "native" to the e2e settings anymore.

[github-actions]

E2E Tests 🚀
This PR will run tests tagged with: @:critical

^{readme  valid tags}

[austin3dickey]

Looks great! Small things:

[austin3dickey]

Thank you! Exciting!

[isabelizimm]

hmmm...with "native" as the default, it looks like the upstream smoke tests hang indefinitely. looking into this!

[isabelizimm]

Looks like our build process for smoke testing is different than upstream, which mostly is fine but they're specifically putting PET into testing paths in the test itself, where we place PET at build time. Since we run our own e2e tests that have the same functionality, I feel pretty okay skipping these smoke tests and logging turning smoke tests on for later work. Does that sound reasonable?

[jthomasmock]

In favor of this, thank you!