Merge pull request #341 from scala-steward/update/akka-actor-2.6.11

Update akka-actor, akka-stream to 2.6.11

Author: ghik

build.sbt

@@ -21,7 +21,7 @@ val springVersion = "4.3.26.RELEASE"
 val typesafeConfigVersion = "1.4.0"
 val commonsIoVersion = "1.3.2"
 val scalaLoggingVersion = "3.9.2"
-val akkaVersion = "2.6.8"
+val akkaVersion = "2.6.11"
 val monixVersion = "3.3.0"
 val mockitoVersion = "3.7.7"
 val circeVersion = "0.13.0"