chore: graduate primer_react_action_menu_display_in_viewport_inside_dialog

[francinelucca]

FF has been fully enabled in dotcom with no issues reported, graduating to default behavior

Changelog

Removed

• primer_react_action_menu_display_in_viewport_inside_dialog, FF on behavior is now the default

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-ui (Learn more about how to run integration tests)

[changeset-bot]

🦋 Changeset detected

Latest commit: 6cb7f10

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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[github-actions]

⚠️ Action required

👋 Hi, this pull request contains changes to the source code that github/github-ui depends on. If you are GitHub staff, test these changes with github/github-ui using the integration workflow. Check the integration testing docs for step-by-step instructions. Or, apply the integration-tests: skipped manually label to skip these checks.

[primer]

🤖 Lint issues have been automatically fixed and committed to this PR.

[Copilot]

Pull request overview

Graduates the previously feature-flagged ActionMenu behavior so that displayInViewport becomes the default when an ActionMenu.Overlay is rendered inside a Dialog, aligning the library’s default behavior with the fully enabled dotcom rollout.

Changes:

• Removed primer_react_action_menu_display_in_viewport_inside_dialog from DefaultFeatureFlags.
• Updated ActionMenu.Overlay to default displayInViewport to true when inside DialogContext (unless explicitly provided).
• Simplified/upgraded related unit tests and Storybook example to reflect the new default behavior.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
packages/react/src/FeatureFlags/DefaultFeatureFlags.ts	Removes the graduated flag from the default feature flag registry.
packages/react/src/ActionMenu/ActionMenu.tsx	Makes “inside Dialog => displayInViewport” the default behavior without a feature flag.
packages/react/src/ActionMenu/ActionMenu.test.tsx	Updates tests to cover the new default behavior and explicit prop overrides.
packages/react/src/ActionMenu/ActionMenu.examples.stories.tsx	Removes FeatureFlags wrapper in the “InsideDialog” example now that behavior is default.

[primer-integration]

👋 Hi from github/github-ui! Your integration PR is ready: https://github.com/github/github-ui/pull/16975

[primer-integration]

Integration test results from github/github-ui:

  CI Passed
  VRT Passed
  Projects Passed

All checks passed!