full pnpx

[xav-ie]

• chore(npx): migrate to pnpx

These edge cases cause users to have both npx and pnpx installed. pnpx is faster and simplifies environment setup.

PR Checklist

• [ ] Addresses an existing open issue: fixes #000
• [ ] That issue was marked as status: accepting prs
• [x] Steps in CONTRIBUTING.md were taken

Overview

Follow up of https://github.com/JoshuaKGoldberg/create-typescript-app/pull/1975. To be rebased and marked ready after that is merged. I am not sure sure how to tell github to make a PR in this repo on top of another PR I already have...

I am happy to break this down further or lump into previous.

🐢