Cut remove_cvref_t from pushmi/traits.h (#1048)

Summary:
- Remove `remove_cvref_t` alias template from `pusmhi/traits.h` in favor of
  `folly::remove_cvref_t` from `folly/Traits.h` which is the same
  definition.
Pull Request resolved: https://github.com/facebook/folly/pull/1048

Reviewed By: ericniebler

Differential Revision: D14402040

Pulled By: yfeldblum

fbshipit-source-id: baba640e5fa410e0c48e666ea004de61b7f12a12

folly/experimental/pushmi/traits.h

@@ -75,9 +75,6 @@ PUSHMI_INLINE_VAR constexpr int sum_v = detail::sum_impl<Is...>();
 template <class...>
 struct typelist;
 
-template <class T>
-using remove_cvref_t = std::remove_cv_t<std::remove_reference_t<T>>;
-
 PUSHMI_CONCEPT_DEF(
   template(class... Args)
   (concept True)(Args...),