Update sbt-ci-release to 1.6.0

Author: scala-steward

project/plugins.sbt

@@ -3,4 +3,4 @@ addSbtPlugin("ch.epfl.scala"    % "sbt-scalafix"   % "0.11.1")
 addSbtPlugin("com.github.sbt"   % "sbt-jacoco"     % "3.5.0")
 addSbtPlugin("com.timushev.sbt" % "sbt-updates"    % "0.6.4")
 addSbtPlugin("org.scalameta"    % "sbt-mdoc"       % "2.5.4")
-addSbtPlugin("com.github.sbt"   % "sbt-ci-release" % "1.5.12")
+addSbtPlugin("com.github.sbt"   % "sbt-ci-release" % "1.6.0")