Update sbt-scalafmt to 2.5.4 (#597)

Co-authored-by: Artur Jurat <[email protected]>

Author: scala-steward

project/plugins.sbt

@@ -1,5 +1,5 @@
 addSbtPlugin("com.github.sbt"    % "sbt-ci-release"  % "1.9.2")
-addSbtPlugin("org.scalameta"     % "sbt-scalafmt"    % "2.5.3")
+addSbtPlugin("org.scalameta"     % "sbt-scalafmt"    % "2.5.4")
 addSbtPlugin("de.heikoseeberger" % "sbt-header"      % "5.10.0")
 addSbtPlugin("com.thesamet"      % "sbt-protoc"      % "1.0.7")
 addSbtPlugin("com.typesafe"      % "sbt-mima-plugin" % "1.1.4")