chore(Dialog): Remove the CSS modules feature flag from the Dialog component

[jonrohan]

Closes https://github.com/github/primer/issues/4309
Closes https://github.com/github/primer/issues/4408

Changelog

New

Changed

Removed

Remove the CSS modules feature flag from the Dialog component

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)

[changeset-bot]

🦋 Changeset detected

Latest commit: 9c1e28a

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

This PR includes changesets to release 1 package

Name	Type
@primer/react	Minor

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[Copilot]

Pull Request Overview

This PR removes the CSS modules feature flag from the Dialog component by eliminating conditionals based on the feature flag and replacing styled component wrappers with BoxWithFallback components.

• Removed toggleStyledComponent wrappers and the useFeatureFlag hook from both Dialog and DialogV1 components.
• Updated tests and stories to remove the FeatureFlags wrapper.

Reviewed Changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
packages/react/src/DialogV1/Dialog.tsx	Removed feature flag logic and updated DialogHeader to use a simpler API.
packages/react/src/DialogV1/Dialog.test.tsx	Removed tests solely relying on feature flag enabled behavior.
packages/react/src/Dialog/Dialog.tsx	Replaced styled component wrappers with BoxWithFallback and removed feature flag checks.
packages/react/src/Dialog/Dialog.test.tsx	Removed feature flag test scenarios.
packages/react/src/Dialog/Dialog.dev.stories.tsx	Removed FeatureFlags wrappers from stories.
.changeset/open-bananas-smile.md	Changeset to document the minor release and removal of CSS modules feature flag.

Files not reviewed (1)

• packages/react/src/DialogV1/Dialog.module.css: Language not supported

Comments suppressed due to low confidence (2)

packages/react/src/Dialog/Dialog.tsx:312

• The removal of toggleStyledComponent and corresponding changes now directly assign data-width and data-height attributes. Please verify that the CSS and component styling consistently consume these attributes across all usage scenarios.

const dimensionProps = enabled ? {'data-width': width, 'data-height': height} : {width, height}

packages/react/src/DialogV1/Dialog.tsx:21

• The DialogHeader component no longer accepts theme and backgroundColor props. Please ensure that consumers and documentation are updated to reflect this API change.

export type DialogHeaderProps = React.PropsWithChildren<HTMLAttributes<HTMLDivElement>> & SxProp

[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	101.85 KB (-0.81% 🔽)
packages/react/dist/browser.umd.js	102.13 KB (-0.67% 🔽)

[primer-integration]

👋 Hi from github/github! Your integration PR is ready: https://github.com/github/github/pull/374821

[primer-integration]

🟢 golden-jobs completed with status success.

[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!

[francinelucca]

❇️