Update sbt-scalafmt to 2.5.4 (#919)

Co-authored-by: Bendix Sältz <bendix@saeltz.de>

Author: scala-steward

project/plugins.sbt

@@ -2,7 +2,7 @@ resolvers += Classpaths.sbtPluginReleases
 
 addSbtPlugin("com.github.sbt" % "sbt-ci-release" % "1.9.2")
 addSbtPlugin("com.eed3si9n"   % "sbt-assembly"   % "0.14.10")
-addSbtPlugin("org.scalameta"  % "sbt-scalafmt"   % "2.5.2")
+addSbtPlugin("org.scalameta"  % "sbt-scalafmt"   % "2.5.4")
 addSbtPlugin("org.scoverage"  % "sbt-scoverage"  % "2.3.1")
 addSbtPlugin("ch.epfl.scala"  % "sbt-scalafix"   % "0.14.2")