Correct the error message in the ExecuteStatelessPayloadV4 function to
reference newPayloadV4 and the Prague fork, instead of incorrectly
referencing newPayloadV3 and Cancun.
This improves clarity during debugging and aligns the error message with
the actual function and fork being validated. No logic is changed.
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Co-authored-by: rjl493456442 <garyrong0905@gmail.com>
