Merge pull request #263 from scala-steward/update/sbt-ci-release-1.8.0

Update sbt-ci-release to 1.8.0

Author: eed3si9n

project/plugins.sbt

@@ -1,5 +1,5 @@
 libraryDependencies += "org.scala-sbt" %% "scripted-plugin" % sbtVersion.value
 
-addSbtPlugin("com.github.sbt" % "sbt-ci-release" % "1.7.0")
+addSbtPlugin("com.github.sbt" % "sbt-ci-release" % "1.8.0")
 
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.2")