The alpine patch includes gettext-dev which is likely also exploited as the same authors have been pushing gettext to projects where their changes have been questioned
It's still the wrong way to go about things. Tests are there for a reason, meaning if they fail you should try to understand them to the point where you can fix the problem (broken test or actual bug) instead of just wantonly distabling tests until you get a green light.
Are you referencing the '-unsafe' suffix in the second link? That is not something to worry about.
This is from Gnulib, which is used by Gettext and other GNU projects. Using 'setlocale (0, NULL)' is not thread-safe on all platforms. Gnulib has modules to work around this, but not all projects want the extra locking. Hence the name '-unsafe'. :)