sbt-header 5.9.0 (was 5.7.0) (#236)

Author: scala-steward

project/plugins.sbt

@@ -1,4 +1,4 @@
-addSbtPlugin("de.heikoseeberger" % "sbt-header"         % "5.7.0")
+addSbtPlugin("de.heikoseeberger" % "sbt-header"         % "5.9.0")
 addSbtPlugin("org.scalameta"     % "sbt-scalafmt"       % "2.4.6")
 addSbtPlugin("com.codecommit"    % "sbt-github-actions" % "0.14.2")
 addSbtPlugin("com.github.sbt"    % "sbt-ci-release"     % "1.5.11")