GHC HEAD's error messages are no longer colorized

This is a regression that I've bisected to commit b3df9e78 (Remove PprStyle param of logging actions). It's difficult to give more information than that, since GitLab won't display the colors, but try compiling a ill typed program like the one below before and after that commit:

module Foo where

f :: Int
f = "abc"

You'll notice the absence of colors after that commit. cc @hsyl20