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>

script/licenses/zed-licenses.toml

@@ -116,6 +116,12 @@ license = "MIT"
 path = 'LICENSE'
 checksum = 'c2cfccb812fe482101a8f04597dfc5a9991a6b2748266c47ac91b6a5aae15383'
 
+[pet-pixi.clarify]
+license = "MIT"
+[[pet-pixi.clarify.git]]
+path = 'LICENSE'
+checksum = 'c2cfccb812fe482101a8f04597dfc5a9991a6b2748266c47ac91b6a5aae15383'
+
 [pet-poetry.clarify]
 license = "MIT"
 [[pet-poetry.clarify.git]]