python: use Python Environment Tools for interpreter discovery

[isabelizimm]

Release Notes

New Features

• Install and compile Python Environment Tools, a Rust-based interpreter discovery system Python: use Python Environment Tools (PET) for interpreter discovery #5886

Bug Fixes

• N/A

QA Notes

Should be able to locate interpreters/start up Python runtimes with setting "python.locator": "native"

---

TODO

• update development compile commands to automatically set everything up
• re-enable native locator tests
• add steps into build CI

[github-actions]

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

[isabelizimm]

Right now, the rust locator is considered experimental and is opt-in only for upstream. I've swapped it for testing purposes, but we'll want to decide what we want as the default. I've played around with it locally, and it seems to be finding everything and is MUCH FASTER, eg, 1-3 seconds to find my 80+ envs. We should do a bit more robust testing before deciding though.