It’s not a lie. Jury nullification does not involve any sort of lying.

The judge will ask you if you can follow the law as it is written. The written law gives laypersons to use their layperson judgement to determine guilt or innocence. That’s derived from the supreme law of the land. Can you follow the supreme law of the land and exercise your judgment as a layperson?

The government is a creation of that law. That government cannot supersede the authority of the law that created it. That government cannot demand that you must exclusively follow those lesser laws that it creates. If you were to ask “Is the constitution part of the written laws I am to follow?”, the only legitimate answer is “Yes, Of course”. But, if asked, that answer will likely be followed by “You are excused with our thanks.” Fortunately, you already know the answer to that question, so you don’t need to ask it. You just need to fulfill your duty, comfortable in the understanding that your duty is as a peer of the defendant, not as an agent of the government.

Until the 6th amendment is repealed, it is not a lie to agree to follow the full law as it is written, even if the government is only willing to provide you instructions involving a small part of a lesser law.