graphics/inkscape: fix build error "default.es_MX.svg:No such file or directory"

The translation file es_MX.po has a fuzzy attribute for the msgid
"Label", so when evaluating this translation, gettext will fall
through to language 'es' for the translation. If
po/locale/es/LC_MESSAGES/inkscape.mo does not exist at the time of
the call, the translation will fail, and "Label" will be returned,
causing the check to fail, preventing writing es_MX.svg.

The order in which languages are processed is determined by the
results of glob.glob, which may vary with filesystem type. In some
build environments, 'es' is processed before 'es_MX', and no problem
occurs. This is not guaranteed, however. In other build environments,
'es_MX' occurs first, and lacking 'es', the translation fails, and
es_MX.svg is not generated.

To remove reliance on a particular ordering of gmofiles, and ensure
build reproducibility, process the translations in two complete
passes -- one to copy the gmo files, and when complete, the second
to actually use the translations to generate the svg files.

PR: 246588
Submitted by: vvd@unislabs.com
Obtained from: https://gitlab.com/inkscape/inkscape/-/merge_requests/2020