fix: move @storybook/preset-scss to devDependencies

It is referenced only by .storybook/main.ts, but sat in dependencies, so
every consumer of this package installed the Storybook + webpack chain
into their production tree — including a vulnerable fast-uri
(GHSA-4c8g-83qw-93j6, host confusion via failed IDN canonicalization).

Production dependency tree drops from 162 entries to 10, and
`npm audit --omit=dev` goes from 1 high to 0.

Author: lakhansamani