Support PEP 723 when detecting python interpreter & virtualenv

[NorthIsUp]

https://peps.python.org/pep-0723/

Python has adopted a format for putting dependencies into a script header and python tooling has implemented ways to run it!

here is an example of uv being used to run a script. It will parse the /// script header, use the specified version of python, create a virtual environment, install dependencies, and then execute the script.

#!/usr/bin/env -S uv run --script
# /// script
# requires-python = ">=3.13"
# dependencies = [
#   "requests", "pydantic",
# ]
# ///
# (note, this is tested on macOS, I don't know if env -S works on gnu systems)

import requests

print(requests.get("example.org"))

right now vscode-python doesn't really know how to handle several aspects of this.

first is language detection. scripts often don't have a file extension so it would be nice to detect uv or pipx in the shabang line to mean "probably python". you could also do more advanced parsing of the entire /// script block.

next is code intelligence, without pythonInterpreter detection there are red squiggles everywhere. when run scripts get their own venv created in a temp location, unfortunately this behavior is tool specific. maybe vscode could create/manage its own!

thanks!

[karthiknadig]

Related: microsoft/vscode-python-environments#185