Update sbt-scalafmt to 2.5.4 in 0.12.x (scalapb#538)

Author: scala-steward

project/plugins.sbt

@@ -5,6 +5,6 @@ libraryDependencies += "com.thesamet.scalapb" %% "compilerplugin" % "0.11.18"
 
 addSbtPlugin("com.typesafe" % "sbt-mima-plugin" % "1.1.4")
 
-addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.2")
+addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.4")
 
 addSbtPlugin("com.github.sbt" % "sbt-ci-release" % "1.5.12")