Fix GitHub mirroring
It looks like the credentials for the ghc-mirror account are lost; we'll need to open a new account.
Due to a large amount of spam we do not allow new users to create repositories, they are "external" users. If you are a new user and want to create a repository, for example for forking GHC, open a new issue on ghc/ghc using the "get-verified" issue template
It looks like the credentials for the ghc-mirror account are lost; we'll need to open a new account.