Revert changes that are unrelated to the memory leak (#5822)

Author: Arkatufus

src/core/Akka/Actor/CoordinatedShutdown.cs

@@ -251,7 +251,7 @@ private ClusterJoinUnsuccessfulReason() { }
         /// <summary>
         /// The <see cref="ActorSystem"/>
         /// </summary>
-        public ExtendedActorSystem System { get; private set; }
+        public ExtendedActorSystem System { get; }
 
         /// <summary>
         /// The set of named <see cref="Phase"/>s that will be executed during coordinated shutdown.
@@ -261,7 +261,7 @@ private ClusterJoinUnsuccessfulReason() { }
         /// <summary>
         /// INTERNAL API
         /// </summary>
-        internal ILoggingAdapter Log { get; private set; }
+        internal ILoggingAdapter Log { get; }
 
         private readonly HashSet<string> _knownPhases;
 
@@ -660,9 +660,6 @@ internal static void InitPhaseActorSystemTerminate(ActorSystem system, Config co
                                 Environment.Exit(0);
                             }
 
-                            coord.System = null;
-                            coord.Log = null;
-                            coord._tasks.Clear(); // Clear the dictionary, just in case it is retained in memory
                             return Done.Instance;
                         });
                     }
@@ -697,7 +694,6 @@ internal static void InitClrHook(ActorSystem system, Config conf, CoordinatedShu
                 system.WhenTerminated.ContinueWith(tr =>
                 {
                     AppDomain.CurrentDomain.ProcessExit -= exitTask;
-                    coord._clrShutdownTasks.Clear(); // Clear the tasks, just in case it is retained in memory
                 });
 
                 coord.AddClrShutdownHook(() =>