ci: use pnpm/action-setup in check-changeset

[Boshen]

Summary

pnpm cache is not being used, let's see if this fixes that

Related issue (if exists)

Types of changes

• Docs change / Dependency upgrade
• Bug fix
• New feature / Improvement
• Refactoring
• Breaking change

Checklist

• I have added changeset via pnpm run changeset.
• I have added tests to cover my changes.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 5530fc2

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

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