[Bug] Duplicate keys are encoded in json

[bilal-fazlani]

import zio.json.*

@jsonDiscriminator("type")
sealed trait GithubIssue derives JsonCodec

@jsonHint("bug")
case class Bug(`type`: String, title: String) extends GithubIssue 

@main def reproduce = {
  val bug:GithubIssue = Bug("bug", "duplicate keys are added to json")
  val json = bug.toJson
  println(json)
}

This prints following

{"type":"bug","type":"bug","title":"duplicate keys are added to json"}