Improve code quality

Author: Jack251970

Flow.Launcher/ViewModel/MainViewModel.cs

@@ -1327,7 +1327,7 @@ private static List<Result> GetHistoryItems(IEnumerable<HistoryItem> historyItem
 
         private async Task QueryResultsAsync(bool searchDelay, bool isReQuery = false, bool reSelect = true)
         {
-            _updateSource?.Cancel();
+            await _updateSource?.CancelAsync();
 
             App.API.LogDebug(ClassName, $"Start query with text: <{QueryText}>");
 
@@ -1906,7 +1906,7 @@ public async Task SetupDialogJumpAsync(nint handle)
             if (DialogJump.DialogJumpWindowPosition == DialogJumpWindowPositions.UnderDialog)
             {
                 // Cancel the previous Dialog Jump task
-                _dialogJumpSource?.Cancel();
+                await _dialogJumpSource?.CancelAsync();
 
                 // Create a new cancellation token source
                 _dialogJumpSource = new CancellationTokenSource();