fix: disable Storybook GitHub Pages deployment workflow

The storybook.yml workflow was also failing with deployment
timeouts and conflicts with deploy-pages.yml.

Both GitHub Pages workflows are now disabled as they are not
critical for the npm package release functionality.

The core workflows remain active:
- release.yml (npm publishing with OIDC)
- security-audit.yml (weekly security scans)
- react-compat.yml (React 18/19 testing)

Refs: #ci-fix

Author: MichaelEakins