* gnu/packages/patches/ghc-haddock-api-fix-haddock.patch: New file.
* gnu/local.mk: Add it.
* gnu/packages/haskell-xyz.scm (ghc-haddock-api): Update to 2.22.0.
[source]: Use the new patch.
[arguments]: Change the 'update-constraints' phase to allow newer
versions of 'QuickCheck' and 'hspec'.
