Update sbt-dotty to 0.5.1 (#311)

Author: scala-steward

project/plugins.sbt

@@ -7,5 +7,5 @@ addSbtPlugin("pl.project13.scala" % "sbt-jmh" % "0.4.0")
 addSbtPlugin("org.scoverage" % "sbt-scoverage" % "1.6.1")
 addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "1.0.0")
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.4.2")
-addSbtPlugin("ch.epfl.lamp" % "sbt-dotty" % "0.5.0")
+addSbtPlugin("ch.epfl.lamp" % "sbt-dotty" % "0.5.1")
 addSbtPlugin("com.codecommit" % "sbt-github-actions" % "0.9.5")