Update sbt-scalajs, scalajs-compiler, ... to 1.20.1 (#415)

Author: softwaremill-ci

project/plugins.sbt

@@ -6,6 +6,6 @@ addSbtPlugin("com.softwaremill.sbt-softwaremill" % "sbt-softwaremill-publish" %
 
 addSbtPlugin("org.jetbrains.scala" % "sbt-ide-settings" % "1.1.3")
 
-addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.19.0")
+addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.20.1")
 
 addSbtPlugin("org.scala-native" % "sbt-scala-native" % "0.5.8")