Potential fix for pull request finding 'Missing Dispose call on local IDisposable'

Co-authored-by: Copilot Autofix powered by AI <223894421+github-code-quality[bot]@users.noreply.github.com>

Author: sophiatev

test/Grpc.IntegrationTests/OrchestrationPatterns.cs

@@ -151,7 +151,7 @@ public async Task ScheduleSubOrchestrationWithTagsAndRetryPolicy()
                 return result;
             }));
         });
-        CancellationTokenSource timeoutTokenSource = new(TimeSpan.FromMinutes(1));
+        using CancellationTokenSource timeoutTokenSource = new(TimeSpan.FromMinutes(1));
 
         // Confirm the first attempt failed
         await server.Client.ScheduleNewOrchestrationInstanceAsync(orchestratorName, input: 1);