Use a higher priority thread here to ensure the dump test runs successfully

tests/Tgstation.Server.Tests/Live/Instance/WatchdogTest.cs

@@ -394,13 +394,17 @@ namespace Tgstation.Server.Tests.Live.Instance
 				KillDD(true);
 				var jobTcs = new TaskCompletionSource();
 				var killTaskStarted = new TaskCompletionSource();
-				var killTask = Task.Run(() =>
+				var killThread = new Thread(() =>
 				{
 					killTaskStarted.SetResult();
 					while (!jobTcs.Task.IsCompleted)
 						KillDD(false);
-				}, cancellationToken);
+				})
+				{
+					Priority = ThreadPriority.AboveNormal
+				};
 
+				killThread.Start();
 				try
 				{
 					await killTaskStarted.Task;
@@ -410,7 +414,7 @@ namespace Tgstation.Server.Tests.Live.Instance
 				finally
 				{
 					jobTcs.SetResult();
-					await killTask;
+					killThread.Join();
 				}
 
 				// these can also happen