Add Noble-issued USDC (`usdc.noble`) to the Regen Ledger currency allowlist

[brawlaphant]

Question for Regen devs and governance stewards:

Since both usdc.noble and usdt.kava follow the exact same param update process — could they be submitted as a single on-chain governance proposal that adds both to the currency_allow_list?

From a coordination and implementation standpoint, bundling them might reduce proposal fatigue and speed up support for native stablecoins.