Update scalatest to 3.2.20 (#378)

Co-authored-by: Mareks Rampāns <8796159+mr-git@users.noreply.github.com>

Author: scala-steward

project/Dependencies.scala

@@ -2,7 +2,7 @@ import sbt._
 
 object Dependencies {
 
-  val scalatest = "org.scalatest" %% "scalatest" % "3.2.19"
+  val scalatest = "org.scalatest" %% "scalatest" % "3.2.20"
   val `slf4j-api` = "org.slf4j" % "slf4j-api" % "2.0.18"
 
   object Logback {