Merge pull request #2305 from scala-steward/update/sbt-ghpages-0.9.0

Update sbt-ghpages to 0.9.0

Author: jatcwang

project/plugins.sbt

@@ -1,7 +1,7 @@
 addSbtPlugin("com.lightbend.paradox" % "sbt-paradox" % "0.10.7")
 addSbtPlugin("com.github.sbt" % "sbt-site" % "1.7.0")
 addSbtPlugin("com.github.sbt" % "sbt-site-paradox" % "1.7.0")
-addSbtPlugin("com.github.sbt" % "sbt-ghpages" % "0.8.0")
+addSbtPlugin("com.github.sbt" % "sbt-ghpages" % "0.9.0")
 addSbtPlugin("org.typelevel" % "sbt-typelevel-ci-release" % "0.8.0")
 addSbtPlugin("org.typelevel" % "sbt-typelevel-mergify" % "0.8.0")
 addSbtPlugin("org.scoverage" % "sbt-scoverage" % "2.3.1")