using remix routes with remix-flat-routes + vite breaks

[lifeiscontent]

Reproduction

run remix routes with a route that works with remix-flat-routes and see the output miss all routes that remix doesn't understand by default

System Info

sh: envinfo: command not found

Used Package Manager

pnpm

Expected Behavior

for remix to understand all routes including from remix-flat-routes

Actual Behavior

seems to assume the config still exists in remix.config.js

[kiliman]

This is fixed in v2.8.1, which should be released soon.

#8916