Update upickle to 4.0.0 (#162)

Author: scala-steward

project/plugins.sbt

@@ -5,4 +5,4 @@ addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.2")
 addSbtPlugin("org.typelevel" % "sbt-tpolecat" % "0.5.1")
 
 // for reading npmDependencies from package.json
-libraryDependencies ++= Seq("com.lihaoyi" %% "upickle" % "3.3.1")
+libraryDependencies ++= Seq("com.lihaoyi" %% "upickle" % "4.0.0")