GKE: auto network detection fails because of deprecated API

[asimpleidea]

While testing on a GKE cluster the auto network detection -- for the Cloud Metadata feature -- I realized that the current way to get them is deprecated, as you can see here https://pkg.go.dev/google.golang.org/api@v0.93.0/container/v1#ProjectsZonesClustersService.Get

This will be fixed, maybe in #98.

[asimpleidea]

UPDATE: after some trial and errors with the new API method, I found out that it doesn't really want a zone but a region, contrary to what it used to be.

Maybe it is just for autopilot, or maybe it is an issue on Google's part but I need to test this is in a non-autopilot GKE cluster too to be sure.