Update sbt-assembly to 2.3.1

Author: scalameta-bot

project/plugins.sbt

@@ -1,5 +1,5 @@
 addSbtPlugin("ch.epfl.scala" % "sbt-scalajs-bundler" % "0.20.0")
-addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "2.3.0")
+addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "2.3.1")
 addSbtPlugin("com.eed3si9n" % "sbt-buildinfo" % "0.13.0")
 addSbtPlugin("com.thesamet" % "sbt-protoc" % "1.0.7")
 addSbtPlugin("org.scala-js" % "sbt-scalajs" % "1.16.0")