Update scalac-scapegoat-plugin to 3.1.1 (#207)

Co-authored-by: scala-steward <162267+scala-steward-for-moia[bot]@users.noreply.github.com>

build.sbt

@@ -154,7 +154,7 @@ lazy val sbtSettings = Seq(cancelable in Global := true)
 
 lazy val scalaFmtSettings = Seq(scalafmtOnCompile := true)
 
-lazy val scapegoatSettings = Seq(ThisBuild / scapegoatVersion := "3.0.3")
+lazy val scapegoatSettings = Seq(ThisBuild / scapegoatVersion := "3.1.1")
 
 lazy val sbtVersionRegex = "v([0-9]+.[0-9]+.[0-9]+)-?(.*)?".r