VSCode Python test discovery not activating the environment

[renan-r-santos]

I'm not sure if this issue should live here or in vscode-python. I have noticed this after fixing the pixi-code extension, see microsoft/vscode-python-debugger#872 for context, but it likely affects conda users too.

When discovering tests using VSCode and pytest, the environment doesn't get properly activated, for example, pixi --shell, as in renan-r-santos/pixi-code/src/pixi/utils.ts. This breaks test discovery that depends on environment variables set during Conda environment activation.

[eleanorjboyd]

This change will end up happening on the Python extension but we will need the testing architecture to call the python environments. Will work on this as it is a priority to get testing working correctly