Upgrade @polkadot/api and @polkadot/util package version to latest (#…

…2821)

Otherwise I'm getting this error:
https://github.com/polkadot-js/api/pull/4952/files#diff-4cab1e3a83a624e52dc0c30047addb28184fdceac6acb930787af9c3aac50706L668
when running `./cumulus/scripts/bridges_rococo_westend.sh
init-bridge-hub-rococo-local` - guess it is related to recent Snowbridge
merge?