tests: date: add another locale test case

tests: date: add another locale test case

On a GNU/Linux system, we have the following:

    $ LC_ALL=en_US.UTF-8 date -u -d 1:00
    Sun Dec 14 01:00:00 AM UTC 2025
    $ LC_ALL=en_US.UTF-8 locale date_fmt
    %a %b %e %r %Z %Y
    $ LC_ALL=en_US.UTF-8 locale t_fmt_ampm
    %I:%M:%S %p

    $ LC_ALL=nl_NL.UTF-8 date -u -d 1:00
    zo 14 dec 2025  1:00:00 UTC
    $ LC_ALL=nl_NL.UTF-8 locale date_fmt
    %a %e %b %Y %k:%M:%S %Z

We respect the locales preference for a leading zero or leading space in
single digit hours.

* tests/date/date-locale-hour.sh: Check that the locales preference for
leading zeros or spaces in single digit hours is used.