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

Author: scala-steward-bot

project/plugins.sbt

@@ -1,5 +1,5 @@
 addSbtPlugin("com.github.sbt" % "sbt-pgp" % "2.3.1")
-addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.19.0")
+addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.20.1")
 addSbtPlugin("com.github.scalaprops" % "sbt-scalaprops" % "0.5.1")
 addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "3.9.21")
 addSbtPlugin("com.github.sbt" % "sbt-release" % "1.4.0")