Bumps [@polkadot/api](https://github.com/polkadot-js/api) from 3.0.1 to 3.1.1.
- [Release notes](https://github.com/polkadot-js/api/releases)
- [Changelog](https://github.com/polkadot-js/api/blob/master/CHANGELOG.md)
- [Commits](https://github.com/polkadot-js/api/commits

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>