bug#79118: CI test failures

Hi Collin,

Today's CI run reports that the new tests
  tests/date/date-ethiopia
  tests/date/date-iran
  tests/date/date-thailand
fail on OpenBSD and macOS.

On OpenBSD, that's expected, because gnulib/lib/strftime.c does not
enable the non-Gregorian calendars on that system (because retrieving
the locale name on OpenBSD pulls in too many dependencies).

On macOS:

That's unexpected. Failure log for date-ethiopia:

++ LC_ALL=C
++ date +%Y
+ current_year=2025
+ export LC_ALL=am_ET.UTF-8
+ LC_ALL=am_ET.UTF-8
++ locale charmap
+ test UTF-8 '!=' UTF-8
++ date -d 2025-09-10 +%Y
+ year_september_10=2017
++ date -d 2025-09-12 +%Y
+ year_september_12=2018
+ test 2017 = 2017
+ test 2017 = 2017
+ test 2018 = 2018
+ case $(date --iso-8601=hours) in
++ date --iso-8601=hours
+ fail=1
+ case $(date --rfc-3339=date) in
++ date --rfc-3339=date
+ fail=1
+ Exit 1

Failure log for date-iran:

++ LC_ALL=C
++ date +%Y
+ current_year=2025
+ export LC_ALL=fa_IR.UTF-8
+ LC_ALL=fa_IR.UTF-8
++ locale charmap
+ test UTF-8 '!=' UTF-8
++ date -d 2025-03-19 +%Y
+ year_march_19=1403
++ date -d 2025-03-22 +%Y
+ year_march_22=1404
+ test 1403 = 1403
+ test 1403 = 1403
+ test 1404 = 1404
+ case $(date --iso-8601=hours) in
++ date --iso-8601=hours
+ fail=1
+ case $(date --rfc-3339=date) in
++ date --rfc-3339=date
+ fail=1

Bruno