Show warning that python isnt installed in select interpreter and/or create environment quick pick

[cwebster-99]

Observed a user navigate to the Select Interpreter status bar item when a python wasnt select and they were shown Create Environment and Enter Interpreter path.

I dont think we should show Create Environment here unless one of the supported managers has a way to bring a Python in the process. It would be nice to also have a warning in this drop down that Python is not detected. Users got stuck in this process and just trying to create environments over and over again

[eleanorjboyd]

🤖 Triage: this reads as a proposed improvement to the interpreter/environment quick-pick when Python is not installed, rather than a regression in an existing supported action. The proposed UI change needs a decision: should Create Environment be hidden when no usable base Python exists, replaced with a route to install Python, or accompanied by an explanation? Marking as a feature request needing a proposal before implementation.