sci-libs/gdal depend on dev-cpp/abseil-cpp although not listed in the ebuild.

dev-cpp/abseil-cpp need C++14 or newer to compile, in it's ebuild "-DCMAKE_CXX_STANDARD=17" is specified under "mycmakeargs", adding that to gdal fixes the build problem.

Will need to test further but this probably becomes a requirement for every package depending on it down the line like gqis to.