Add support for edition 2023

[friscoMad]

I am unsure how to do that in this plugin, in grpc-java it was done in this commit

This is the error with 1.4.1:
XXX: is an editions file, but code generator protoc-gen-grpckt hasn't been updated to support editions yet. Please ask the owner of this code generator to add support or switch back to proto2/proto3