Include bytestring-0.12 in GHC-9.8.1

The breaking change in bytestring-0.12 is the same as in text-2.1, namely using Data.Array.Byte instead of their own ByteArray# wrappers. text-2.1 is going to be included in GHC-9.8, AFAIK, but bytestring-0.12 isn't.

This is silly. Both changes are "as dangerous" and I don't see a good reason to spread the changes across multiple major GHCs than to annoy maintainers: The changes required (if any) are similar. The bytestring-0.12 is virtually non-existent and build-plans with it are essentially non-testable at large. (ghc lib depends on bytestring, so if I want to use e.g. inspection-testing - I'm out of luck).

Alternative: don't include text-2.1 in GHC-9.8. I'll be ok with that too, i.e. hold on updating both of the libraries.