Update sbt-scalafmt to 2.5.5

Author: 47erbot

project/plugins.sbt

@@ -1,4 +1,4 @@
 resolvers += Resolver.sonatypeRepo("snapshots")
-addSbtPlugin("org.scalameta"     % "sbt-scalafmt"  % "2.5.4")
+addSbtPlugin("org.scalameta"     % "sbt-scalafmt"  % "2.5.5")
 addSbtPlugin("org.typelevel"     % "sbt-tpolecat"  % "0.5.2")
 addSbtPlugin("io.higherkindness" % "sbt-mu-srcgen" % "0.34.0")