Add stablecoin amount to Polkadot treasury

there are several million in stablecoins within the Polkadot treasury but they are not being priced
https://defillama.com/treasuries

<img width="1297" alt="Image" src="https://github.com/user-attachments/assets/8e9f13c8-e683-4136-9285-da47caf4306d" />