refactor: non-null assertion operator

Author: boray

src/lib/mina/v1/transaction-validation.ts

@@ -244,10 +244,11 @@ async function verifyAccountUpdate(
       };
 
       let verificationKeyRaw = account.zkapp?.verificationKey;
+      assert(verificationKeyRaw !== undefined, 'Account does not have a verification key');
       let verificationKey = verificationKeyRaw?.data;
-      assert(verificationKey !== undefined, 'Account does not have a verification key');
+      assert(verificationKey !== undefined, 'Account does not have a verification key data');
 
-      const isVkValid = await checkVkValidity(verificationKeyRaw!);
+      const isVkValid = await checkVkValidity(verificationKeyRaw);
       if (!isVkValid)
         throw Error(`The verification key hash is not consistent with the provided data`);