Add ghc 9.2.5

[MangoIV]

ghc 9.2.5 is out, it would be nice to have it in haskell.nix

https://www.haskell.org/ghc/download_ghc_9_2_5.html

Additional context

I would like to do this myself, but I would need a hint at where materialization is documented like it is done in #1566

thanks in advance.

[amesgen]

I think this can be closed as #1779 got merged.