Don't create a Task if we don't have to.

src/MySqlConnector/MySqlClient/MySqlConnection.cs

@@ -261,7 +261,7 @@ internal Task<T> AdaptTask<T>(Task<T> task)
 
 		internal ValueTask<T> AdaptTask<T>(ValueTask<T> task)
 		{
-			if (!Synchronous)
+			if (!Synchronous || task.IsCompletedSuccessfully)
 				return task;
 
 			return new ValueTask<T>(task.AsTask().GetAwaiter().GetResult());