Update sbt-header to 5.6.5

Author: 47erbot

project/plugins.sbt

@@ -2,7 +2,7 @@ addSbtPlugin("org.scala-exercises" % "sbt-exercise"             % "0.7.1")
 addSbtPlugin("com.github.sbt"      % "sbt-ci-release"           % "1.5.10")
 addSbtPlugin("org.scalameta"       % "sbt-mdoc"                 % "2.2.24")
 addSbtPlugin("org.scalameta"       % "sbt-scalafmt"             % "2.4.6")
-addSbtPlugin("de.heikoseeberger"   % "sbt-header"               % "5.6.0")
+addSbtPlugin("de.heikoseeberger"   % "sbt-header"               % "5.6.5")
 addSbtPlugin("com.alejandrohdezma" % "sbt-github"               % "0.11.2")
 addSbtPlugin("com.alejandrohdezma" % "sbt-github-header"        % "0.11.2")
 addSbtPlugin("com.alejandrohdezma" % "sbt-github-mdoc"          % "0.11.2")