Update scalafix-core to 0.9.4

Author: scala-steward

project/plugins.sbt

@@ -10,6 +10,6 @@ val scalaJSVersion = Option(System.getenv("SCALAJS_VERSION")).filter(_.nonEmpty)
 addSbtPlugin("org.scala-js"           % "sbt-scalajs"              % scalaJSVersion)
 addSbtPlugin("org.portable-scala"     % "sbt-scalajs-crossproject" % "0.6.0")
 addSbtPlugin("org.scala-lang.modules" % "sbt-scala-module"         % "1.0.14")
-addSbtPlugin("ch.epfl.scala"          % "sbt-scalafix"             % "0.9.0")
+addSbtPlugin("ch.epfl.scala"          % "sbt-scalafix"             % "0.9.4")
 addSbtPlugin("com.eed3si9n"           % "sbt-buildinfo"            % "0.7.0")
 addSbtPlugin("com.typesafe.sbt"       % "sbt-pgp"                  % "0.8.3")