react-router improvements

[43081j]

Linking here for tracking:
remix-run/react-router#13721

There's quite a few easy wins, but the chunky ones seem to be:

• Replace express in the serve package
• Replace prompts with clack (looks like it may have originally come from clack, or is very similar)

[MichaelDeBoey]

• chore: remove unused npm-run-all dependency remix-run/react-router#13718
• chore(node): cleanup unused dependencies remix-run/react-router#13723
• refactor(create-react-router): use native Node.js instead of recursive-readdir remix-run/react-router#13735
• refactor: use native Node.js instead of fs-extra remix-run/react-router#13736
• perf: use replaceAll for slash normalisation remix-run/react-router#13738
• chore: remove unused files remix-run/react-router#13740
• fix(cloudflare): remove tsup from peerDependencies remix-run/react-router#13757
• chore(deps): update Babel deps to latest remix-run/react-router#13758
• chore: cleanup root package.json remix-run/react-router#13759
• chore(node): remove unused file remix-run/react-router#13760
• chore(react-router): remove unused code remix-run/react-router#13761
• fix(node): remove old "install" package exports remix-run/react-router#13762