Merge pull request scala#371 from scala-steward/update/sbt-scalajs-1.20.1

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

Author: lrytz

project/plugins.sbt

@@ -1,3 +1,3 @@
 addSbtPlugin("org.scala-lang.modules" % "sbt-scala-module" % "3.3.0")
-addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.19.0")
+addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.20.1")
 addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "1.3.2")