fix(on-chain-state-mgmt-zkapp-ui.js): change proof extraction from tr…

…ansaction.prove() to correctly get proof data

This change is necessary because the previous implementation was not correctly extracting the proof data from the transaction.prove() promise.

tests/artifacts/javascript/on-chain-state-mgmt-zkapp-ui.js

@@ -78,7 +78,7 @@ updateButton.addEventListener('click', async (event) => {
       );
     });
 
-    const [proof] = await transaction.prove();
+    const [proof] = (await transaction.prove()).proofs;
 
     if (verificationKey) {
       let isVerified = await verify(proof, verificationKey.data);