Merge pull request #518 from scala-steward/update/1.2.x/sbt-ci-release-1.12.0

[1.2.x] sbt-ci-release 1.12.0 (was 1.11.2)

Author: mkurz

project/plugins.sbt

@@ -1,3 +1,3 @@
 addSbtPlugin("com.typesafe"   % "sbt-mima-plugin" % "1.1.6")
 addSbtPlugin("org.scalameta"  % "sbt-scalafmt"    % "2.6.1")
-addSbtPlugin("com.github.sbt" % "sbt-ci-release"  % "1.11.2")
+addSbtPlugin("com.github.sbt" % "sbt-ci-release"  % "1.12.0")