Use TemplateHaskellQuotes rather than TemplateHaskell extension

TemplateHaskell can't be used in boot libraries as not all platforms support evaluating Template Haskell splices. Therefore we should use TemplateHaskellQuotes to be more precise about the requirements which a module places on the host system.

System/OsString/Internal/Types.hs

@@ -2,7 +2,7 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE PackageImports #-}
 {-# LANGUAGE RankNTypes #-}
-{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE TemplateHaskellQuotes #-}
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE TypeApplications #-}