Update GoReleaser to v2 config

[philrz]

What's Changing

This updates our GoReleaser config to their "v2" syntax. It also points our Release workflow at a newer Action that defaults to GoReleaser v2.

Why

I went to do some local tasks with my Homebrew-installed goreleaser and found it refused to work off the .goreleaser.yaml at current tip-of-main because it's not in "v2" format.

Details

I tested this all out using a personal fork of the super repo by tagging a release version. You can see/download the artifacts at https://github.com/philrz/super/releases and the updated Homebrew Tap at https://github.com/philrz/homebrew-tap.

Note how GoReleaser now creates a Homebrew "Cask" rather than the "Formula" it did in the past. I had to give myself a crash course on this but the tl;dr is that it does seem the Cask concept is a better match for our approach of installing a precompiled binary rather than compiling from source. In line with Homebrew conventions this means when we do a GA release the super.rb will land below a Casks/ directory in our homebrew-tap repo. This all worked fine in my test by doing brew install philrz/tap/super on a scratch host.