chore(cabal): update haskell language edition to GHC2021

This includes a good set of default language extensions that are
often used by us. It frees us of explicitly importing common extensions.

Ref: https://ghc.gitlab.haskell.org/ghc/doc/users_guide/exts/control.html#extension-GHC2021

Signed-off-by: Taimoor Zaeem <taimoorzaeem@gmail.com>

src/library/PostgREST/ApiRequest/QueryParams.hs

@@ -4,8 +4,7 @@
 --
 -- This module is in charge of parsing all the querystring values in an url, e.g.
 -- the select, id, order in `/projects?select=id,name&id=eq.1&order=id,name.desc`.
-{-# LANGUAGE LambdaCase    #-}
-{-# LANGUAGE TupleSections #-}
+{-# LANGUAGE LambdaCase #-}
 module PostgREST.ApiRequest.QueryParams
   ( parse
   , QueryParams(..)