Reusable Go setup action

[dsimansk]

In knative/func repo I've tried to consolidate Go version into single point of configuration.

I wonder if that can be stored on knative/actions level as well. For the convenience to use the same version.

And in addition if we could reuse it reusable actions (aka inception of inceptions :))?

[dprotaso]

It would be nice if this could be synced up with prow.

And potentially configure different go versions for different branches