Make HandleActorTaskSchedulerMessage method protected virtual (akkadotnet#6763)

* Make `HandleActorTaskSchedulerMessage` method `protected virtual`

* Update API Verify list

---------

Co-authored-by: Aaron Stannard <[email protected]>

Author: Arkatufus

src/core/Akka.API.Tests/verify/CoreAPISpec.ApproveCore.DotNet.verified.txt

@@ -100,6 +100,8 @@ namespace Akka.Actor
         public static Akka.Actor.IActorRef GetCurrentSelfOrNoSender() { }
         public static Akka.Actor.IActorRef GetCurrentSenderOrNoSender() { }
         public Akka.Actor.IInternalActorRef GetSingleChild(string name) { }
+        [Akka.Annotations.InternalApiAttribute()]
+        protected virtual void HandleActorTaskSchedulerMessage(Akka.Dispatch.SysMsg.ActorTaskSchedulerMessage m) { }
         public void Init(bool sendSupervise, Akka.Dispatch.MailboxType mailboxType) { }
         public Akka.Actor.Internal.ChildRestartStats InitChild(Akka.Actor.IInternalActorRef actor) { }
         public void Invoke(Akka.Actor.Envelope envelope) { }
@@ -3127,6 +3129,16 @@ namespace Akka.Dispatch.SysMsg
         public ActorTask(System.Threading.Tasks.Task task) { }
         public System.Threading.Tasks.Task Task { get; }
     }
+    [Akka.Annotations.InternalApiAttribute()]
+    public sealed class ActorTaskSchedulerMessage : Akka.Dispatch.SysMsg.SystemMessage
+    {
+        public ActorTaskSchedulerMessage(Akka.Dispatch.ActorTaskScheduler scheduler, System.Threading.Tasks.Task task, object message) { }
+        public ActorTaskSchedulerMessage(System.Exception exception, object message) { }
+        public System.Exception Exception { get; }
+        public object Message { get; }
+        public void ExecuteTask() { }
+        public override string ToString() { }
+    }
     public sealed class Create : Akka.Dispatch.SysMsg.SystemMessage
     {
         public Create(Akka.Actor.ActorInitializationException failure = null) { }

src/core/Akka.API.Tests/verify/CoreAPISpec.ApproveCore.Net.verified.txt

@@ -100,6 +100,8 @@ namespace Akka.Actor
         public static Akka.Actor.IActorRef GetCurrentSelfOrNoSender() { }
         public static Akka.Actor.IActorRef GetCurrentSenderOrNoSender() { }
         public Akka.Actor.IInternalActorRef GetSingleChild(string name) { }
+        [Akka.Annotations.InternalApiAttribute()]
+        protected virtual void HandleActorTaskSchedulerMessage(Akka.Dispatch.SysMsg.ActorTaskSchedulerMessage m) { }
         public void Init(bool sendSupervise, Akka.Dispatch.MailboxType mailboxType) { }
         public Akka.Actor.Internal.ChildRestartStats InitChild(Akka.Actor.IInternalActorRef actor) { }
         public void Invoke(Akka.Actor.Envelope envelope) { }
@@ -3119,6 +3121,16 @@ namespace Akka.Dispatch.SysMsg
         public ActorTask(System.Threading.Tasks.Task task) { }
         public System.Threading.Tasks.Task Task { get; }
     }
+    [Akka.Annotations.InternalApiAttribute()]
+    public sealed class ActorTaskSchedulerMessage : Akka.Dispatch.SysMsg.SystemMessage
+    {
+        public ActorTaskSchedulerMessage(Akka.Dispatch.ActorTaskScheduler scheduler, System.Threading.Tasks.Task task, object message) { }
+        public ActorTaskSchedulerMessage(System.Exception exception, object message) { }
+        public System.Exception Exception { get; }
+        public object Message { get; }
+        public void ExecuteTask() { }
+        public override string ToString() { }
+    }
     public sealed class Create : Akka.Dispatch.SysMsg.SystemMessage
     {
         public Create(Akka.Actor.ActorInitializationException failure = null) { }

src/core/Akka/Actor/ActorCell.DefaultMessages.cs

@@ -14,6 +14,7 @@
 using Akka.Event;
 using Debug = Akka.Event.Debug;
 using System.Globalization;
+using Akka.Annotations;
 
 namespace Akka.Actor
 {
@@ -334,7 +335,8 @@ internal void SystemInvoke(ISystemMessage envelope)
             SysMsgInvokeAll(new EarliestFirstSystemMessageList((SystemMessage)envelope), CalculateState());
         }
 
-        private void HandleActorTaskSchedulerMessage(ActorTaskSchedulerMessage m)
+        [InternalApi]
+        protected virtual void HandleActorTaskSchedulerMessage(ActorTaskSchedulerMessage m)
         {
             //set the current message captured in the async operation
             //current message was cleared earlier when the async receive handler completed

src/core/Akka/Dispatch/SysMsg/ISystemMessage.cs

@@ -588,7 +588,8 @@ public ActorTask(Task task)
     /// <summary>
     /// TBD
     /// </summary>
-    internal sealed class ActorTaskSchedulerMessage : SystemMessage
+    [InternalApi] 
+    public sealed class ActorTaskSchedulerMessage : SystemMessage
     {
         private readonly ActorTaskScheduler _scheduler;
         private readonly Task _task;