Chore/dep upgrade 2026 09

[pdavies88]

Description of the Change

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Changelog Entry

Added - New feature
Changed - Existing functionality
Deprecated - Soon-to-be removed feature
Removed - Feature
Fixed - Bug fix
Security - Vulnerability
Developer - Non-functional update

Credits

Props @username, ...

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added Critical Flows, Test Cases, and/or End-to-End Tests to cover my change.
• All new and existing tests pass.

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🦋 Changeset detected

Latest commit: 5ca9089

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

This PR includes changesets to release 2 packages

Name	Type
@headstartwp/next	Minor
@headstartwp/block-primitives	Major

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Project	Deployment	Actions	Updated
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[pdavies88]

@chriseagle so this branch and #958 which is a superset of this branch are the first step imo.

Remove any extra dependencies not core to the library ie: linaria, vanilla extract, storybook

Update all packages to their latest stable minor

#958 takes some larger important steps. Moves us off of 10up-toolkit to WP-Vite-plugins and updates Next to v16. Still keeping everything on React 18.3 to support the Pages Router but this basically does everything but upgrade to React 19 which to me is the first logical step as we'd still support everything and then have the packages in an updated spot to go to 19 and the focus is exclusively on 19 upgrades