Reliably and quickly fetch activated environment variables for conda

[karrtikr]

conda run is more reliable than conda activate : #19967
conda activate command is much faster than conda run : conda/conda#11814

We could do a mixture of these two approaches in the extension and return which ever came back with the environment variables faster.

However note this can change with #11039, where we potentially get rid of using conda activate commands, so it's best to tackle this issue after that.

[fulcus]

#19967 is not fixed, I am still getting the same error on prerelease v2023.5.10741016

We failed to start a TensorBoard session due to the following error: Command failed: conda run -n cv --no-capture-output python /Users/fulco/.vscode/extensions/ms-python.python-2023.5.10741016/pythonFiles/get_output_via_markers.py /Users/fulco/.vscode/extensions/ms-python.python-2023.5.10741016/pythonFiles/printEnvVariables.py bash: conda: command not found

[karrtikr]

That is not the same error as #19967. Please open a new issue and we'll be happy to look into it.