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).
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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).