CXX-3003 Remove documentation of bsoncxx/util directory (#1259)

Author: eramongodb

src/bsoncxx/include/bsoncxx/v_noabi/bsoncxx/fwd.hpp

@@ -348,13 +348,6 @@
 /// Provides headers declaring entities in @ref bsoncxx::v_noabi::types::bson_value.
 ///
 
-///
-/// @dir bsoncxx/v_noabi/bsoncxx/util
-/// Headers provided by this directory are deprecated.
-///
-/// @deprecated To be removed in an upcoming major release.
-///
-
 ///
 /// @namespace bsoncxx::v_noabi
 /// Declares entities whose ABI stability is NOT guaranteed.