tests: remove custom --without-postgresql-tests test option (#39641)

pytest.config was deprecated in pytest 5 and it's not worth adapting all
tests.

tests/conftest.py

@@ -6,16 +6,6 @@ import pytest
 from utilities import EmailsMocking, SMSMocking, HttpRequestsMocking
 
 
-def pytest_addoption(parser):
-    parser.addoption('--without-postgresql-tests', action='store_true',
-                     help='disable tests requiring postgresql')
-
-
-def pytest_runtest_setup(item):
-    if 'postgresql' in item.keywords and item.config.option.without_postgresql_tests is True:
-        pytest.skip('skipped (PostgreSQL are disabled on command line)')
-
-
 def site_options(request, pub, section, variable, value):
     config = ConfigParser.ConfigParser()
     path = os.path.join(pub.app_dir, 'site-options.cfg')

tests/utilities.py

@@ -44,10 +44,6 @@ known_elements = KnownElements()
 
 
 def create_temporary_pub(sql_mode=False, templates_mode=False, lazy_mode=False):
-    if sql_mode is True:
-        if pytest.config.getoption('without_postgresql_tests'):
-            pytest.skip("unsupported configuration")
-            return
     if get_publisher():
         get_publisher().cleanup()
         cleanup()

tox.ini

@@ -16,7 +16,7 @@ setenv =
 passenv =
     USER
 deps =
-    pytest>=3.6,<5
+    pytest>=3.6
     pytest-mock
     pytest-cov
     pytest-django