Update Autocomplete.dev.stories.tsx to no longer use styled-components

[llastflowers]

Closes https://github.com/github/primer/issues/5671

Changelog

Removed

Removed Autocomplete.dev.stories.tsx because it only had one story and that story no longer has a purpose after removal of sx prop

Rollout strategy

• Patch release
• Minor release
• Major release; if selected, include a written rollout or migration plan
• None; if selected, include a brief description as to why

Testing & Reviewing

Merge checklist

• Added/updated tests
• Added/updated documentation
• Added/updated previews (Storybook)
• Changes are SSR compatible
• Tested in Chrome
• Tested in Firefox
• Tested in Safari
• Tested in Edge
• (GitHub staff only) Integration tests pass at github/github (Learn more about how to run integration tests)

[github-actions]

size-limit report 📦

Path	Size
packages/react/dist/browser.esm.js	90.2 KB (0%)
packages/react/dist/browser.umd.js	90.38 KB (0%)