Remove the unused known key and name for `failIO`
This removes the variables for the known key and the name of the failIO operation, as they are apparently nowhere used in GHC’s source code, and thus resolves part of #26677 (closed).
This removes the variables for the known key and the name of the failIO operation, as they are apparently nowhere used in GHC’s source code, and thus resolves part of #26677 (closed).