Update sbt-typelevel-mergify to 0.5.4 (#3183)

Author: scala-steward

project/plugins.sbt

@@ -11,4 +11,4 @@ addSbtPlugin("pl.project13.scala" % "sbt-jmh" % "0.4.6")
 addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "1.3.2")
 addSbtPlugin("org.scalameta" % "sbt-mdoc" % "2.3.7")
 addSbtPlugin("org.scoverage" % "sbt-scoverage" % "2.0.9")
-addSbtPlugin("org.typelevel" % "sbt-typelevel-mergify" % "0.5.3")
+addSbtPlugin("org.typelevel" % "sbt-typelevel-mergify" % "0.5.4")