tests: detect use of --nomigrations through pytestconfig

Module pytest_django.migrations was removed in pytest_django 4.2.0.

tests/conftest.py

@@ -27,7 +27,6 @@ from django.core.cache import cache
 from django.core.management import call_command
 from django.db import connection
 from django.db.migrations.executor import MigrationExecutor
-from pytest_django.migrations import DisableMigrations
 
 from authentic2 import hooks as a2_hooks
 from authentic2.a2_rbac.utils import get_default_ou
@@ -283,14 +282,6 @@ def concurrency(settings):
     return 100
 
 
-@pytest.fixture
-def migrations():
-    from django.conf import settings
-
-    if isinstance(settings.MIGRATION_MODULES, DisableMigrations):
-        pytest.skip('this test requires native migrations')
-
-
 @pytest.fixture
 def oidc_client(db, ou1):
     client = OIDCClient.objects.create(

tests/test_concurrency.py

@@ -23,7 +23,9 @@ from authentic2.models import Attribute, AttributeValue
 
 
 @pytest.mark.slow
-def test_attribute_value_uniqueness(migrations, transactional_db, simple_user, concurrency):
+def test_attribute_value_uniqueness(transactional_db, simple_user, concurrency, pytestconfig):
+    if pytestconfig.getoption('nomigrations'):
+        pytest.skip('running migrations is required for this test')
     # disable default attributes
     Attribute.objects.update(disabled=True)