gettext: Accept `pass`/`fail` as results

The test is currently emitting results in this way:

Testing supported locales:
ar_QA.utf8: fail
ar_SA.utf8: fail
cs_CZ.utf8: fail
da_DK.utf8: fail
de_DE.utf8: fail
el_GR.utf8: fail
en_GB.utf8: fail
en_US.utf8: fail
es_AR.utf8: fail
es_ES.utf8: fail
es_MX.utf8: fail
fi_FI.utf8: fail
fr_CA.utf8: fail
fr_FR.utf8: fail
hu_HU.utf8: fail
id_ID.utf8: fail
it_IT.utf8: fail
ms_MY.utf8: fail
nb_NO.utf8: fail
nl_NL.utf8: fail
pl_PL.utf8: fail
pt_BR.utf8: fail
pt_PT.utf8: fail
ro_RO.utf8: fail
ru_RU.utf8: fail
sk_SK.utf8: fail
sv_SE.utf8: fail
th_TH.utf8: fail
tr_TR.utf8: fail
zh_CN.utf8: fail
zh_HK.utf8: fail
31 test(s) failed

See https://lava.collabora.co.uk/scheduler/job/1827695#L5089

However, the current regex only matched uppercase characters, expecting PASSED/FAILED.