Use std::less as a default comparator instead of operator< for additional algorithms

[dmitriy-sobolev]

Summary: C++ standard replaces operator< as a default comparator for many algorithms with std::less since c++20 (see std::sort as an example). Let's do the same replacement for the additional algorithms. std::less is a more genetic alternative to operator<, thus it can be done even for c++17 mode.

The issue is motivated by this discussion: https://github.com/oneapi-src/oneDPL/pull/1692#discussion_r1679303718.

URLs: additional_algorithms.rst