Refactor scheduled tasks & publishing cancellation

src/Umbraco.Web/Scheduling/BackgroundTaskRunner.cs

@@ -96,21 +96,6 @@ namespace Umbraco.Web.Scheduling
                 StartUp();
         }
 
-        /// <summary>
-        /// Returns the current cancellation token
-        /// </summary>
-        public CancellationToken CurrentCancellationToken
-        {
-            get
-            {
-                if (_tokenSource == null)
-                {
-                    throw new InvalidOperationException("The token source has not been created which means the task runner has not been started");
-                }
-                return _tokenSource.Token;
-            }
-        }
-
         /// <summary>
         /// Gets the number of tasks in the queue.
         /// </summary>