Correctly advertise editions support

[mkruskal-google]

No description provided.

[puellanivis]

Thank you for the attention, but the github.com/golang/protobuf module is frozen except for essential bug fixes and regressions from one of the more recent versions.

[mkruskal-google]

I would actually label this a regression/bug fix. AFAICT this plugin should support edition 2023 just fine because it uses the official golang protoc plugin infra, edition 2023 doesn't affect RPC codegen, and it already sets FEATURE_SUPPORTS_EDITIONS by copying SupportedFeatures. It just fails to specify the edition window it supports, so anyone using this plugin will hit protoc errors when they try to upgrade to editions

[puellanivis]

A good point. 🤔 I do wonder though, how likely is it that people would still be using this protoc-gen-go rather than the newer one?

But still, also reasonable, and measured.

(Still needs a proper 👍 from someone with dev access.)

[mkruskal-google]

FWIW I hit this trying to migrate someone to editions that was using this plugin :). I ended up just switching them to the newer one, but I figured there might be edge cases where that's not as much of an option.