refactor: Actions to Delegates

Engine.Core/Abstract/Assignable/IAssignableGameManager.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Syntriax.Engine.Core.Abstract;
 
 /// <summary>
@@ -10,7 +8,7 @@ public interface IAssignableGameManager : IAssignable
     /// <summary>
     /// Event triggered when the <see cref="IGameManager"/> value has has been assigned a new value.
     /// </summary>
-    Action<IAssignableGameManager>? OnGameManagerAssigned { get; set; }
+    event OnGameManagerAssignedDelegate? OnGameManagerAssigned;
 
     /// <inheritdoc cref="IGameManager" />
     IGameManager GameManager { get; }
@@ -23,4 +21,6 @@ public interface IAssignableGameManager : IAssignable
     /// <see cref="true"/>, if the value given assigned successfully assigned, <see cref="false"/> if not.
     /// </returns>
     bool Assign(IGameManager gameManager);
+
+    delegate void OnGameManagerAssignedDelegate(IAssignableGameManager sender);
 }