refactor: use rolldown for packages

[joshblack]

Follow up to: https://github.com/primer/react/pull/7263 but a little smaller 👀

This PR updates our internal packages and styled-react to use rolldown over rollup. Rolldown is a rollup API compatible library that is using Rust for improved build performance ✨

Changelog

New

Changed

• Update rollup usage to rolldown in:
  • doc-gen
  • mcp
  • styled-react
• Add dependencies explicitly to styled-react/package.json so they were external to the build

Removed

Rollout strategy

• [x] Patch release
• [x] None; if selected, include a brief description as to why

For most libraries, this should be internal-only but styled-react I added a changeset for since we needed to add dependencies to package.json

[changeset-bot[bot]]

🦋 Changeset detected

Latest commit: 62669218de4c507cf6877df6a21a8d0bd8ccec3f

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

This PR includes changesets to release 1 package

Name	Type
@primer/styled-react	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR