Investigate necessitate of the binary targets in the prisma schema.

[alasdairwilson]

generator client {
  provider      = "prisma-client-js"
  binaryTargets = ["native", "debian-openssl-3.0.x", "linux-musl-openssl-3.0.x"]
  enums         = true
}

This change to binary targets to add musl to the existing debian openssl was added in #300 as an emergency fix to an outage that occurred due to a redeploy while there was an active course that day. The wisdom of this notwithstanding (🤣 ) I can only assume the issue was either caused by the image update in #290 which had never been deployed and so might have broken it or a change in fly.io machine configuration.

I question whether we should be defining binaryTargets here at all, but it does work for now (and hopefully forever).