🐛 Bug: Should use pnpx, not npx, to install

[JoshuaKGoldberg]

Bug Report Checklist

• I have tried restarting my IDE and the issue persists.
• I have pulled the latest main branch of the repository.
• I have searched for related issues and found none that matched my issue.

Expected

Since pnpm add, pnpm install, and other pnpm commands are used to manage packages, pnpx should be used to execute dependencies in terminals.

Actual

npx is used, which means sometimes a script can't be found. I've seen all-contributors: cannot be found errors running npx all-contributors-cli.

Additional Info

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