`spin update` An easier way to update to latest spin version

[me-diru]

I wondered if there is an easier way to update the spin CLI than installing the artifact again using the installation docs for every new release

Would like to know your input on the same.

[lann]

Certainly possible but self-update mechanisms are quite tricky to get right, especially cross-platform.

[asteurer]

@me-diru You might find the Verman plugin useful in this situation