DoAfter Refactor (#13225)

Co-authored-by: DrSmugleaf <drsmugleaf@gmail.com>

Content.Server/Disease/Components/DiseaseSwabComponent.cs

@@ -1,4 +1,3 @@
-using System.Threading;
 using Content.Shared.Disease;
 
 namespace Content.Server.Disease.Components
@@ -20,10 +19,6 @@ namespace Content.Server.Disease.Components
         /// </summary>
         public bool Used = false;
         /// <summary>
-        /// Token for interrupting swabbing do after.
-        /// </summary>
-        public CancellationTokenSource? CancelToken;
-        /// <summary>
         /// The disease prototype currently on the swab
         /// </summary>
         [ViewVariables]