Update scalatest to 3.2.9 (#341)

build.sbt

@@ -9,7 +9,7 @@ lazy val versionOf = new {
   val log4cats      = "2.1.0"
   val log4s         = "1.9.0"
   val scalaCheck    = "1.15.4"
-  val scalaTest     = "3.2.8"
+  val scalaTest     = "3.2.9"
   val zio           = "1.0.7"
   val scribe        = "3.5.4"
   val silencer      = "1.7.3"