https://github.com/haskell-nix/hnix/pull/922 removed a few build-depends
from hnix.cabal which are still required until the following constraints
apply to stackage:
* relude >= 1.0.0.0
* semialign >= 1.2
Luckily, we can simply revert a few commits from master and add
semialign-indexed to resolve this without too much hassle nor
extra-packages (which may cause us trouble through propagation of a
newer relude).