Remove duplicate reseed:detroit command

[emilyjablonski]

In Detroit, we still have yarn db:reseed and yarn db:reseed:detroit

We should remove the :detroit suffixed command but keep that functionality, so that we reseed with the Detroit listings but have the same command name as core.

It also looks like the partners site cypress tests over there are using db:reseed:detroit and the public cypress tests are using db:reseed so it is possible there is work if the public sites tests fail on the Detroit data.

QA Notes: There isn't anything outside of a dev environment or CI to QA. A dev can ensure they can reseed locally and that the CI tests did pass.