Update sbt-typelevel to 0.6.6

Author: typelevel-steward[bot]

project/plugins.sbt

@@ -1,4 +1,4 @@
 addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.11.0")
 addSbtPlugin("org.scala-native" % "sbt-scala-native" % "0.4.9")
 addSbtPlugin("org.portable-scala" % "sbt-scala-native-crossproject" % "1.2.0")
-addSbtPlugin("org.typelevel" % "sbt-typelevel" % "0.4.19")
+addSbtPlugin("org.typelevel" % "sbt-typelevel" % "0.6.6")