Effects: Basic: LANGUAGE: rm unused ConstraintKinds

Author: Anton-Latukha

src/Nix/Effects/Basic.hs

@@ -1,6 +1,5 @@
 {-# LANGUAGE ApplicativeDo #-}
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}