Remove support for sx from FilteredActionList component

[llastflowers]

Closes #6789

Current sx usage: 0

✅ Don't need to separately update github-ui components to use @primer/styled-react

Changelog

Removed

Remove support for sx from the FilteredActionList component, and any associated stories, docs, and tests

Rollout strategy

• Major release; if selected, include a written rollout or migration plan

This component currently has 0 sx usage in dotcom, and therefore does not need the @primer/styled-react wrapper. this will be confirmed again before merging.

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)

[changeset-bot]

🦋 Changeset detected

Latest commit: b8fad14

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
@primer/react	Major
@primer/styled-react	Major

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions]

👋 Hi, this pull request contains changes to the source code that github/github depends on. If you are GitHub staff, we recommend testing these changes with github/github using the integration workflow. Thanks!

[primer-integration]

👋 Hi from github/github-ui! Your integration PR is ready: https://github.com/github/github-ui/pull/2844

[primer-integration]

🟢 ci completed with status success.

[Copilot]

Pull Request Overview

This PR removes support for the sx prop from the FilteredActionList component as part of the migration away from styled-components. Since there is no current usage of sx on this component in dotcom, this change is safe to implement as a breaking change.

Key changes:

• Replace Box components with plain div elements and corresponding CSS classes
• Remove sx prop from component interface and implementation
• Add CSS classes to maintain equivalent styling functionality

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
FilteredActionList.tsx	Remove sx prop from interface, replace BoxWithFallback with div, update ActionList styling
FilteredActionList.module.css	Add ActionList CSS class with flex-grow styling
FilteredActionListLoaders.tsx	Replace Box components with div elements and CSS classes
FilteredActionListLoaders.module.css	Add LoadingSpinner and LoadingSkeletonContainer CSS classes
.changeset/mighty-lizards-lick.md	Add changeset entry for major version bump

[liuliu-dev]

Looks great! 🎉

[pksjce]

Shouldn't we be removing below as well?

const StyledHeader = styled.div`
  box-shadow: 0 1px 0 ${get('colors.border.default')};
  z-index: 1;
`