Nobody should directly need to reference these packages.
This is technically a breaking change. However:
- Package dns was exporting a NewBuilder method. This should never have been necessary to use, but if so, it can be replaced by importing the "grpc" package and then using resolver.Get("dns").
- Package passthrough was not exporting any symbols and there was never a need to even blank-import it.
After as much searching as possible, it appears nobody in the open source community is referencing either of these packages.
