ci-base: install gettext package that has msgfmt binary
This addresses feedback in !34 (merged). Technically we didn't install gettext before, so it's not a regression, but installing it shouldn't hurt either.
This instance will be upgraded to Heptapod 17.5.3 on 2024-12-12 between 10:00 and 11:00 UTC+1
This addresses feedback in !34 (merged). Technically we didn't install gettext before, so it's not a regression, but installing it shouldn't hurt either.