Merge pull request #566 from scala-steward/update/pekko-actor-1.4.0

Update pekko-actor, pekko-slf4j, ... to 1.4.0

Author: mergify[bot]

build.sbt

@@ -1,7 +1,7 @@
 
 val Library = new {
   object Version {
-    val pekko = "1.2.1"
+    val pekko = "1.4.0"
     val pekkoHttp = "1.2.0"
     // val pekkoHttpCirce = "1.39.2"
     val circe = "0.14.14"