Allow redux 6 as dependeny

[frontendphil]

The library has no problems with redux 6, so allow it as a peer dep.

[khamiltonuk]

I think Kraken is up to date with redux at version 4.0.1
to check the latest version, you can check the releases page
https://github.com/reduxjs/redux/releases

[frontendphil]

This issue is about kraken requesting only version 6 of redux as a peer dependency. This is why we also get warnings in the client installation.