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

[llastflowers]

Closes https://github.com/github/primer/issues/5591

Changelog

Changed

Changed AvatarStack.dev.stories.tsx to no longer use styled-components

Removed

Removed the Sx Prop story for AvatarStack because it 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	90.03 KB (0%)
packages/react/dist/browser.umd.js	90.13 KB (0%)

[Copilot]

Pull Request Overview

This PR removes styled-components usage from AvatarStack development stories by eliminating the SxProp story that demonstrated the sx prop functionality. The change aligns with the broader effort to move away from styled-components in the codebase.

• Removed the SxProp story from AvatarStack.dev.stories.tsx
• Updated the end-to-end test configuration to remove the corresponding test case

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
packages/react/src/AvatarStack/AvatarStack.dev.stories.tsx	Removed the SxProp story that demonstrated styled-components functionality
e2e/components/AvatarStack.test.ts	Removed the test configuration entry for the deleted SxProp story

[joshblack]

One note for dev stories, I think we'll hold off on removing them until we remove the sx support in the component since they're being used in our e2e tests at the moment.

Let me know what you think / if this makes sense or not 👀

[llastflowers]

One note for dev stories, I think we'll hold off on removing them until we remove the sx support in the component since they're being used in our e2e tests at the moment.

Let me know what you think / if this makes sense or not 👀

Oh yeah, that makes sense! We can just let this PR sit for now, in that case 😸