In #19127 I converted fse.watchFile to fs.promises.watchFile, which apparently doesn't exist.

Revert to using the synchronous fs.watchFile to fix this issue, although we should probably be using fs.promises.watch:

Using fs.watch() is more efficient than fs.watchFile and fs.unwatchFile. fs.watch should be used instead of fs.watchFile and fs.unwatchFile when possible.

I'll move this to fs.watch in a follow-up PR.