fix some warnings in hlint plugin

Author: michaelpj

plugins/hls-hlint-plugin/src/Ide/Plugin/Hlint.hs

@@ -134,8 +134,11 @@ import           Development.IDE.Spans.Pragmas                      (LineSplitTe
                                                                      lineSplitTextEdits,
                                                                      nextPragmaLine)
 import           GHC.Generics                                       (Generic)
+#if MIN_VERSION_apply_refact(0,12,0)
+#else
 import           System.Environment                                 (setEnv,
                                                                      unsetEnv)
+#endif
 import           Text.Regex.TDFA.Text                               ()
 -- ---------------------------------------------------------------------
 
@@ -383,7 +386,7 @@ getHlintConfig pId =
     <$> usePropertyAction #flags pId properties
 
 runHlintAction
- :: (Eq k, Hashable k, Show k, Show (RuleResult k), Typeable k, Typeable (RuleResult k), NFData k, NFData (RuleResult k))
+ :: (Hashable k, Show k, Show (RuleResult k), Typeable k, Typeable (RuleResult k), NFData k, NFData (RuleResult k))
  => IdeState
  -> NormalizedFilePath -> String -> k -> IO (Maybe (RuleResult k))
 runHlintAction ideState normalizedFilePath desc rule = runAction desc ideState $ use rule normalizedFilePath