Better report success when nodejs.exe creation fails

[bersbersbers]

Related to #180, I see this in my console:

C:\Users\bers>nodeenv x
 * Install prebuilt node (17.8.0) ..... done.
You do not have sufficient privilege to perform this operation.
You do not have sufficient privilege to perform this operation.
Error: Failed to create nodejs.exe link

C:\Users\bers>nodeenv x
 * Environment already exists: x

To me, this looks like the first operation failed, and I only see that upon trying again.

(I have the impression that this hinders pyright startup on my system, but I am not experienced enough with either to say if that is in fact working as intended or not.)