bug#72039: [core-updates] ki18n test failure of KCatalogTest (locales problem?)

[Leo Famulari <leo@famulari.name>]

On core-updates commit 736939037346, ki18n fails its test suite like
this:

********* Start testing of KCatalogTest *********
Config: Using QtTest library 5.15.10, Qt 5.15.10 (x86_64-little_endian-lp64 shared (dynamic) release build; by GCC 11.4.0), unknown unknown
PASS   : KCatalogTest::initTestCase()
QWARN  : KCatalogTest::testLookup() kf.i18n: The value of the LANGUAGE environment variable: "fr_CH:fr_CH:fr_CH:fr_CH:fr_CH:fr_CH:fr_CH:fr_CH:fr_CH:fr_CH:fr_CH:fr_CH:fr_CH:fr_CH:fr_CH:fr_CH" ( size: 95 ),
 was longer than (and consequently truncated to) the max. length of: 54
FAIL!  : KCatalogTest::testLookup() Compared values are not the same
   Actual   (c.name())                          : "New Zealand"
   Expected (QStringLiteral("Nouvelle-Zélande")): "Nouvelle-Z\u00E9lande"
   Loc: [/tmp/guix-build-ki18n-5.114.0.drv-0/ki18n-5.114.0/autotests/kcatalogtest.cpp(40)]
PASS   : KCatalogTest::cleanupTestCase()
Totals: 2 passed, 1 failed, 0 skipped, 0 blacklisted, 2ms
********* Finished testing of KCatalogTest *********
<end of output>
Test time =   0.01 sec
----------------------------------------------------------
Test Failed.
"kcatalogtest" end time: Jul 10 17:16 UTC
"kcatalogtest" time elapsed: 00:00:00
----------------------------------------------------------

It expects the value "New Zealand", but instead receives
"Nouvelle-Z\u00E9lande".

And there is a warning about the LANGUAGE environment variable, although
this variable is defined in the 'environment-variables' debugging file
created when building with '--keep-failed'.

It fails the same with ki18n version 5.116.0, which is the latest
version in the 5 series.

Any ideas?