Do not automatically trigger environment discovery at startup

[karrtikr]

Already brought it up with @DonJayamanne but opening this issue to track it.

I understand with the current design of kernel picker this is not possible. However, with the new design discovery can be triggered when the list is opened instead, so this can be avoided.

[karrtikr]

FYI we have been recommending folks to disable Jupyter extension for related issues: microsoft/vscode-python#20446 (comment)

[karrtikr]

@DonJayamanne Any status on prioritizing this?

microsoft/vscode-python#21010 (comment)

[thoth291]

Look at my comment here: microsoft/vscode-python#21010 (comment)

[DonJayamanne]

Done

[DonJayamanne]

This shuold now be done, #15261