Update sbt-scalafmt to 2.5.4 (#179)

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Author: scala-steward

project/plugins.sbt

@@ -1,7 +1,7 @@
 addSbtPlugin("org.scala-js"  % "sbt-scalajs"         % "1.18.1")
 addSbtPlugin("ch.epfl.scala" % "sbt-scalajs-bundler" % "0.21.1")
 
-addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.2")
+addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.4")
 addSbtPlugin("org.typelevel" % "sbt-tpolecat" % "0.5.2")
 
 // for reading npmDependencies from package.json