Update sbt-scalajs, scalajs-compiler, ... to 1.20.1

Author: scala-steward

project/plugins.sbt

@@ -1,6 +1,6 @@
 addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "1.3.2")
 
-addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.18.2")
+addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.20.1")
 
 addSbtPlugin("com.thoughtworks.sbt-scala-js-map" % "sbt-scala-js-map" % "4.1.1")