GNU gettext simply is a PITA on certain platforms (i.e. Windows, musl
Linux, etc.) and currently it's not possible to cleanly remove i18n
from the build process, making building Ghostty on the aforementioned
platforms difficult. By providing users with a way to opt-out of the
i18n mechanisms (or opt-in, on platforms where i18n is disabled by
default) we can make sure that people at least have *some* way of
building Ghostty before i18n mechanisms can be integrated neatly.