python: Detect pixi environments automatically (#22635)

Goal: Allow zed to locate [`pixi`](https://github.com/prefix-dev/pixi)
environments

Changes:
- Uses a newer release of
[`python-environment-tools`](https://github.com/microsoft/python-environment-tools)
with the new `pet-pixi` create
- Adds `PythonEnvironmentKind::Pixi` as a possible environment kind, to
allow the rest of the code to detect the environment

I tested the changes locally. It found the correct pixi environment and
I was able to run `pytest` through the UI icon.


Release Notes:

- Added detection for pixi-environments

---------

Co-authored-by: Piotr Osiewicz <24362066+osiewicz@users.noreply.github.com>

crates/languages/src/python.rs

@@ -542,6 +542,7 @@ static ENV_PRIORITY_LIST: &'static [PythonEnvironmentKind] = &[
     PythonEnvironmentKind::VirtualEnvWrapper,
     PythonEnvironmentKind::Venv,
     PythonEnvironmentKind::VirtualEnv,
+    PythonEnvironmentKind::Pixi,
     PythonEnvironmentKind::Conda,
     PythonEnvironmentKind::Pyenv,
     PythonEnvironmentKind::GlobalPaths,