Update sbt-example to 4.2.0

Author: scala-steward

project/plugins.sbt

@@ -1,5 +1,5 @@
 addSbtPlugin("com.thoughtworks.sbt-best-practice" % "sbt-best-practice" % "4.0.1")
 
-addSbtPlugin("com.thoughtworks.example" % "sbt-example" % "4.0.6")
+addSbtPlugin("com.thoughtworks.example" % "sbt-example" % "4.2.0")
 
 addSbtPlugin("pl.project13.scala" % "sbt-jmh" % "0.3.2")