Set fixed locale in tests

[LEdoian]

Test used local names of months, causing a fail.

To reproduce original issue, run LC_TIME=ja_JP.UTF-8 pytest on branch main. Fails with

>       assert "Released 24-Feb" in result
E       AssertionError: assert 'Released 24-Feb' in '\n\n1.0\n---\n\nCopyright 2015\nReleased 24- 2月\n\nSome details\n'

test_all.py:115: AssertionError

Does not happen anymore with this fix.

An alternative would be to only set the locale in the specific test or only set LC_TIME, but I believe this creates more stable testing environment overall.

[jaraco]

I tried replicating the issue, but was unable to, either on my mac or on Ubuntu 22.04:

<user>@8ad8585efe82 /src main [1] # env LC_TIME=ja_JP.UTF-8 /tox/python/bin/pytest
=============================================================== test session starts ================================================================
platform linux -- Python 3.11.0rc1, pytest-7.1.2, pluggy-1.0.0
rootdir: /src, configfile: pytest.ini
plugins: black-0.3.12, mypy-0.9.1, flake8-1.1.1, cov-3.0.0, enabler-1.3.0, checkdocs-2.7.1
collected 21 items                                                                                                                                 

. .                                                                                                                                          [  5%]
test_all.py ..........                                                                                                                       [ 55%]
docs/conf.py ...                                                                                                                             [ 70%]
rst/__init__.py ...                                                                                                                          [ 85%]
rst/linker.py ...                                                                                                                            [100%]

-------- coverage: platform linux, python 3.11.0-candidate-1 ---------
Name                               Stmts   Miss  Cover   Missing
----------------------------------------------------------------
/etc/python3.11/sitecustomize.py       0      0   100%
docs/conf.py                           6      0   100%
rst/__init__.py                        1      0   100%
rst/linker.py                        107     27    75%   14-15, 34, 100, 128-129, 138-141, 176-178, 184-185, 193, 201, 205-213, 217
test_all.py                           56      1    98%   71
----------------------------------------------------------------
TOTAL                                170     28    84%

======================================================================= mypy =======================================================================

Success: no issues found in 4 source files
=============================================================== 20 passed in 11.01s ================================================================