Update sbt-mima-plugin to 1.1.5

Author: scala-steward

project/plugins.sbt

@@ -1,5 +1,5 @@
 addSbtPlugin("com.github.sbt"     % "sbt-pgp"         % "2.3.1")
 addSbtPlugin("com.github.sbt"     % "sbt-release"     % "1.4.0")
-addSbtPlugin("com.typesafe"       % "sbt-mima-plugin" % "1.1.4")
+addSbtPlugin("com.typesafe"       % "sbt-mima-plugin" % "1.1.5")
 addSbtPlugin("org.scalameta"      % "sbt-scalafmt"    % "2.5.6")
 addSbtPlugin("pl.project13.scala" % "sbt-jmh"         % "0.4.8")