Update sbt-scalajs, scalajs-compiler, ... to 1.20.1 (#442)

Author: scala-steward

project/plugins.sbt

@@ -6,5 +6,5 @@ addSbtPlugin("io.spray" % "sbt-revolver" % "0.10.0")
 addSbtPlugin("io.taig" % "sbt-blowout-yaml-circe" % "0.2.1")
 addSbtPlugin("io.taig" % "sbt-houserules" % "0.11.6")
 addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "1.3.2")
-addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.19.0")
+addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.20.1")
 addSbtPlugin("org.scalameta" % "sbt-mdoc" % "2.7.2")