security(web-client): update Storybook to remove immer (Prototype Pol…

…lution)

Invocation:

    npx sb upgrade --prerelease

This is currently a 6.5.0 alpha release, but we can update to 6.5.0 once
that's stable.

Upstream issue: storybookjs/storybook#16093

CVEs for immer:

* GHSA-33f9-j839-rf8h (CVSS 9.8 Critical)
* GHSA-c36v-fmgq-m8hx (CVSS 7.5 High)