build(core): fix storybook build config for safari

[coryrylan]

PR Checklist

Please check if your PR fulfills the following requirements:

• [ ] Tests for the changes have been added (for bug fixes / features)
• [ ] Docs have been added / updated (for bug fixes / features)
• [ ] If applicable, have a visual design approval

PR Type

What kind of change does this PR introduce?

• [ ] Bugfix
• [ ] Feature
• [ ] Code style update (formatting, local variables)
• [ ] Refactoring (no functional changes, no api changes)
• [x] Build related changes
• [ ] CI related changes
• [ ] Documentation content changes
• [ ] clarity.design website / infrastructure changes
• [ ] Other... Please describe:

What is the new behavior?

Minor adjustment that prevents the storybook build from compiling to older JS targets. Speeds up the storybook watch and enables newer JS features to be used (async generators es2020+). This only applies to the storybook dev build and does not impact the library build.

Does this PR introduce a breaking change?

• [ ] Yes
• [x] No

Other information