tests: always mock emails in backoffice tests (#33815)

tests/test_backoffice_pages.py

@@ -56,7 +56,7 @@ def pytest_generate_tests(metafunc):
         metafunc.parametrize('pub', ['pickle', 'sql', 'pickle-templates'], indirect=True)
 
 @pytest.fixture
-def pub(request):
+def pub(request, emails):
     pub = create_temporary_pub(
             sql_mode=bool('sql' in request.param),
             templates_mode=bool('templates' in request.param)