Add throttle combinator without bucket size in parameters (#23808)

* +str Add throttle combinator without bucket size in parameters

* Add mima filter plus comment formatting

* Reviwed throttle messages across all classes

* move mima filter to 2.4.6

* change to throttleEven, plus grammar fixes

* fix formatting

* changed mima filter according to new API

* fixes accoring to feedback

akka-stream/src/main/scala/akka/stream/impl/Throttle.scala

@@ -71,8 +71,7 @@ import scala.concurrent.duration.{ FiniteDuration, _ }
         override def onPull(): Unit = pull(in)
       }
 
-      setHandler(in, handler)
-      setHandler(out, handler)
+      setHandlers(in, out, handler)
       // After this point, we no longer need the `handler` so it can just fall out of scope.
     }