fix: use pnpm staged publishing

[JoviDeCroock]

Summary

• Uses pnpm stage publish for the pnpm workspace publish path.
• Pins pnpm to 11.3.0 so the stage command is available.
• Preserves Changesets tag/GitHub release creation from the staging helper.
• Fixes the dependency install command to use the lockfile normally.

Verification

• node --check .github/scripts/stage-packages.mjs
• pnpm exec prettier --check .github/scripts/stage-packages.mjs .github/workflows/release.yml
• Workflow YAML parsed locally.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 04b0226

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