DEV: allow `dev:populate` rake task in production environment. (PR #13777)

To use this rake task in production ALLOW_DEV_POPULATE environment variable should be set to “1”.


This is a bit tricky, you will still need to run bundle in production to get it to work. I guess it will work OK as long as you set it on ENV in your container and do a rebuild.

@SamSaffron yes, it will work. Also, they can manually run ALLOW_DEV_POPULATE=1 bundle install in production.