Remove sx from the SelectPanel component

[liuliu-dev]

Remove sx from the SelectPanel component
Closes #5826

sx usage: 0

Rollout strategy

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

[changeset-bot]

🦋 Changeset detected

Latest commit: 595d693

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

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[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!

[github-actions]

size-limit report 📦

Path	Size
packages/react/dist/browser.esm.js	87.92 KB (+0.01% 🔺)
packages/react/dist/browser.umd.js	88.2 KB (+0.15% 🔺)

[primer-integration]

👋 Hi from github/github-ui! Your integration PR is ready: https://github.com/github/github-ui/pull/2021

[primer-integration]

🟢 ci completed with status success.

[Copilot]

Pull Request Overview

This PR removes the sx prop from the SelectPanel component as part of the ongoing migration away from styled-components to CSS modules. The change replaces the inline sx styling with a dedicated CSS class for the text input margin and removes the sx prop from the component interface and FilteredActionList.

Key Changes

• Removed sx prop from SelectPanel component interface
• Replaced inline sx styling for TextInput with CSS module class
• Added new CSS class .TextInput with margin styling in SelectPanel.module.css

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
packages/react/src/SelectPanel/SelectPanel.tsx	Removed sx prop from component interface and replaced inline styling with CSS class
packages/react/src/SelectPanel/SelectPanel.module.css	Added .TextInput CSS class with margin styling
.changeset/lemon-jokes-camp.md	Added changeset documenting the major breaking change

[llastflowers]

Maybe we should keep this comment, but move it near the relevant code in the css module?

[github-actions]

👋 Hi, there are new commits since the last successful integration test. We recommend running the integration workflow once more, unless you are sure the new changes do not affect github/github. Thanks!