Update sbt-scala-native-crossproject, ... to 1.3.1 (#207)

Author: scala-steward

project/plugins.sbt

@@ -1,5 +1,5 @@
 addSbtPlugin("org.scala-lang.modules" % "sbt-scala-module" % "3.0.1")
-addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "1.2.0")
-addSbtPlugin("org.portable-scala" % "sbt-scala-native-crossproject" % "1.2.0")
+addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "1.3.1")
+addSbtPlugin("org.portable-scala" % "sbt-scala-native-crossproject" % "1.3.1")
 addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.13.0")
 addSbtPlugin("org.scala-native" % "sbt-scala-native" % "0.4.10")