ghc: 7.8.3

Starts the process of closing [31609](https://github.com/Homebrew/homebrew/issues/31609). The patches previous in :DATA have been merged with this release and consequently are no longer required. There is also currently no dev build available, so that has been scrapped as well.
I didn't think it did, but without me leaving it there I was getting failures by the brew audit locally :/. Just going to check what the bot failed me on this time.