See playframework/play-json#759
Shouldn't also the Scala version be updated in a GHA workflow file? At the time the pull request got opened by scala-steward the exact same version (3.1.3-RC2) could be found in https://github.com/playframework/play-json/blob/9bd7d5ec6b6f3f42eeb63fbedd3efa7ac30005e5/.github/workflows/build-test.yml#L41. However, scala steward did not update the version in that file...

According to the default configs

• scala-steward/docs/repo-specific-configuration.md

  Line 61 in 0a4d1a0

  # Default: [".scala", ".sbt", ".sbt.shared", ".sc", ".yml", "pom.xml"]

  and

• scala-steward/modules/core/src/main/scala/org/scalasteward/core/repoconfig/UpdatesConfig.scala

  Lines 76 to 77 in d43fad1

  	val defaultFileExtensions: Set[String] =
  	Set(".scala", ".sbt", ".sbt.shared", ".sc", ".yml", "pom.xml")

shouldn't those yml files be updated as well?