Bump Cabal submodule
Adapts GHC to the factoring-out of Cabal-syntax
(see https://github.com/haskell/cabal/pull/7620).
Fixes #20991 (closed).
Adapts GHC to the factoring-out of Cabal-syntax
(see https://github.com/haskell/cabal/pull/7620).
Fixes #20991 (closed).