Push margin-top of TimelineBody +1px

[llastflowers]

Relates to https://github.com/github/primer/issues/6438
Corresponding PVC PR: primer/view_components#3976

Changelog

Changed

Added +1px to the margin-top of TimelineBody to improve visual alignment of elements

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

Good test stories:

• https://primer.style/react/storybook/?path=/story/components-timeline-features--timeline-break
• https://primer.style/react/storybook/?path=/story/components-timeline-features--with-inline-links

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: 2acbcc8

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	Patch

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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. Or, apply the integration-tests: skipped manually label to skip these checks.

[Copilot]

Pull request overview

Adjusts TimelineBody spacing in @primer/react’s Timeline component to improve visual alignment by nudging the top margin down by 1px.

Changes:

• Updates TimelineBody’s margin-top from var(--base-size-4) to calc(var(--base-size-4) + 1px).
• Adds a targeted stylelint-disable-next-line primer/spacing for the calc(...) spacing expression.

[primer-integration]

👋 Hi from github/github-ui! Your integration PR is ready: https://github.com/github/github-ui/pull/15018

[primer-integration]

Integration test results from github/github-ui:

  CI Passed
  VRT Passed
  Projects Passed

All checks passed!

[llastflowers]

Integration tests passed but not reporting for CI. Marking as skipped to unblock