Remove redundant Cy_Ref_impl comparison operators

This will fix clang 'ambiguous operation' errors

Cython/Utility/CyObjects.cpp

@@ -188,11 +188,6 @@
                 return uobj == rhs.uobj;
             }
 
-            template <typename U>
-            friend bool operator==(const Cy_Ref_impl<U>& lhs, const Cy_Ref_impl<T>& rhs) noexcept {
-                return lhs.uobj == rhs.uobj;
-            }
-
             template <typename U>
             bool operator==(U* rhs) const noexcept {
                 return uobj == rhs;
@@ -216,11 +211,6 @@
                 return uobj != rhs.uobj;
             }
 
-            template <typename U>
-            friend bool operator!=(const Cy_Ref_impl<U>& lhs, const Cy_Ref_impl<T>& rhs) noexcept {
-                return lhs.uobj != rhs.uobj;
-            }
-
             template <typename U>
             bool operator!=(U* rhs) const noexcept {
                 return uobj != rhs;