Update sbt-scalafix to 0.9.9

Author: scala-steward

project/plugins.sbt

@@ -1,5 +1,5 @@
 addSbtPlugin("io.github.davidgregory084" % "sbt-tpolecat" % "0.1.8")
-addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.9.8")
+addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.9.9")
 addSbtPlugin("org.wartremover" % "sbt-wartremover" % "2.4.3")
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.2.1")
 addSbtPlugin("org.scalameta" % "sbt-mdoc" % "2.0.2")