Update sbt-scoverage to 1.9.1 (#2271)

Author: scala-steward

project/plugins.sbt

@@ -10,7 +10,7 @@ addSbtPlugin("de.heikoseeberger" % "sbt-header" % "5.6.0")
 addSbtPlugin("io.github.davidgregory084" % "sbt-tpolecat" % "0.1.20")
 addSbtPlugin("pl.project13.scala" % "sbt-jmh" % "0.4.3")
 addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "1.1.0")
-addSbtPlugin("org.scoverage" % "sbt-scoverage" % "1.9.0")
+addSbtPlugin("org.scoverage" % "sbt-scoverage" % "1.9.1")
 
 // This is only here so that Scala Steward updates the version in sbt/package.scala too.
 addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.9.31")