Adding Delay to CheckForSmoke to Prevent Flakes (#6396)

## Summary of changes
There are a couple of `NoException` tests that make use of
`CheckForSmoke` failing after app shutdown so adding delay to try
testing

## Reason for change
To try preventing some flake.

Author: link04

tracer/test/Datadog.Trace.ClrProfiler.IntegrationTests/SmokeTests/SmokeTestBase.cs

@@ -153,6 +153,8 @@ protected async Task CheckForSmoke(bool shouldDeserializeTraces = true, int expe
             {
                 Assert.True(string.IsNullOrEmpty(result.StandardError), $"Expected no errors in smoke test: {result.StandardError}");
             }
+
+            await Task.Delay(5000);
         }
     }
 }