devel/boost-libs: unbreak some C++14 consumers with GCC after r479222

Boost 1.68 changed System ABI[1] for C++14 but due to a GCC bug it's
disabled for C++ >= 17. As our Boost package is built in C++17
consumers cannot use C++14. So, disable the new ABI for the affected
GCC versions regardless of C++ standard.

[1] https://github.com/boostorg/system/commit/7b6dcf6ac668

PR: 231447
Reported by: Piotr Kubaj