Update sbt-scoverage to 2.4.0 (#610)

Author: scala-steward

project/plugins.sbt

@@ -4,4 +4,4 @@ addSbtPlugin("com.github.sbt" % "sbt-pgp" % "2.3.1")
 addSbtPlugin("org.scalameta" % "sbt-mdoc" % "2.7.2")
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.5")
 addSbtPlugin("org.scoverage" % "sbt-coveralls" % "1.3.15")
-addSbtPlugin("org.scoverage" % "sbt-scoverage" % "2.3.1")
+addSbtPlugin("org.scoverage" % "sbt-scoverage" % "2.4.0")