Update dependency org.specs2:specs2-core to v5

Author: renovate[bot]

build.sbt

@@ -17,7 +17,7 @@ lazy val octopushAkka = project
         "com.typesafe.akka" %% "akka-http-core" % "10.5.3",
         "com.typesafe.akka" %% "akka-http-xml" % "10.5.3",
         "com.iheart" %% "ficus" % "1.5.2",
-        "org.specs2" %% "specs2-core" % "4.20.4" % "test"
+        "org.specs2" %% "specs2-core" % "5.5.1" % "test"
       ),
       Test/fork := true,
       scalariformAutoformat := true,