build(deps): Update sbt-mdoc from 2.8.2 to 2.9.0

Author: scala-center-steward[bot]

project/build.sbt

@@ -8,7 +8,7 @@ addSbtPlugin("com.eed3si9n" % "sbt-buildinfo" % "0.13.1")
 addSbtPlugin("pl.project13.scala" % "sbt-jmh" % "0.4.8")
 addSbtPlugin("com.github.sbt" % "sbt-git" % "2.1.0")
 addSbtPlugin("com.github.sbt" % "sbt-ci-release" % "1.11.2")
-addSbtPlugin("org.scalameta" % "sbt-mdoc" % "2.8.2")
+addSbtPlugin("org.scalameta" % "sbt-mdoc" % "2.9.0")
 addSbtPlugin("org.scala-debugger" % "sbt-jdi-tools" % "1.1.1")
 addSbtPlugin("com.github.sbt" % "sbt-native-packager" % "1.11.7")
 addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.14.6")