Provide --protocol-params-file in build-raw tests with Plutus scripts
cardano-api 11.0.0.0 (IntersectMBO/cardano-api#1181) makes `makeUnsignedTx` error when Plutus scripts are present but protocol parameters are missing, instead of silently omitting `script_data_hash`. Two existing tests built Plutus txs without `--protocol-params-file` and so now fail. Point both at the existing offline-protocol-params-preview.json fixture used by the other tests in the same module.