update runtime code

重构了OperationSystem的机制。从列表模式修改为链模式

Assets/YooAsset/Runtime/FileSystem/Operation/FSLoadBundleFileOperation.cs

@@ -1,5 +1,4 @@
-using UnityEngine;
-
+
 namespace YooAsset
 {
     internal abstract class FSLoadBundleOperation : AsyncOperationBase
@@ -18,11 +17,6 @@ namespace YooAsset
         /// 下载大小
         /// </summary>
         public long DownloadedBytes { protected set; get; } = 0;
-
-        /// <summary>
-        /// 终止下载任务
-        /// </summary>
-        public abstract void AbortDownloadOperation();
     }
 
     internal sealed class FSLoadBundleCompleteOperation : FSLoadBundleOperation
@@ -41,8 +35,5 @@ namespace YooAsset
         internal override void InternalUpdate()
         {
         }
-        public override void AbortDownloadOperation()
-        {
-        }
     }
 }