[Constitutional] AIP: Remove Cost Cap on Arbitrum Nova

This proposal ends an outdated subsidy by letting Nova fees reflect real L1 costs, which is now only about 2x lower than Arbitrum One. We agree that expending more treasury to chase marginal savings no longer drives adoption because teams that need ultra-cheap capacity are moving to Orbit chains. Redirecting those funds to higher-impact initiatives will improve overall capital efficiency while users still enjoy low absolute gas fees.