Update dependency org.scalameta:sbt-mdoc to v2.7.1

Author: renovate[bot]

project/plugins.sbt

@@ -3,7 +3,7 @@ addSbtPlugin("se.marcuslonnberg" % "sbt-docker" % "1.9.0")
 addSbtPlugin("com.github.sbt" % "sbt-ci-release" % "1.5.10")
 addSbtPlugin("com.eed3si9n" % "sbt-buildinfo" % "0.10.0")
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.4.6")
-addSbtPlugin("org.scalameta" % "sbt-mdoc" % "2.5.2")
+addSbtPlugin("org.scalameta" % "sbt-mdoc" % "2.7.1")
 addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.12.0")
 addSbtPlugin("com.thesamet" % "sbt-protoc" % "1.0.6")
 addSbtPlugin("com.sourcegraph" % "sbt-sourcegraph" % "0.4.3")