gh-137481: fix test expectations on some platforms

[kulikjak]

The recently introduced test_locale_calendar_long_weekday_names expects abbreviated weekday names to be three characters long, which is not the case on Oracle Solaris. In case of "pt_PT.UTF-8" locale:

>>> import calendar
>>> print(list(calendar.day_name))
['segunda-feira', 'terça-feira', 'quarta-feira', 'quinta-feira', 'sexta-feira', 'sábado', 'domingo']
>>> print(list(calendar.day_abbr))
['segunda', 'terça', 'quarta', 'quinta', 'sexta', 'sábado', 'domingo']

This makes the test work in such cases as well.

• Issue: Needless abbreviation of day names in certain locale in calendar #137481

[serhiy-storchaka]

Great! I have some suggestions that reflect the original purpose of the test.

[kulikjak]

Thanks for the suggestions, it's fixed now.

EDIT: and retested, just to be sure ;).

[serhiy-storchaka]

LGTM. 👍

Thank you for your continued support of Python on Solaris.

[kulikjak]

Thank you for merging my changes 😉.