manager: fix agenda's role edition when partial booking enabled (#85999)

tests/manager/test_all.py

@@ -479,17 +479,18 @@ def test_add_agenda_and_set_role(app, admin_user, manager_user):
     assert agenda.desk_set.count() == 1
 
 
-def test_agenda_set_role_with_partial_booking(settings, app, manager_user):
+def test_agenda_set_role_with_partial_booking(settings, app, admin_user):
     settings.PARTIAL_BOOKING_ENABLED = True
 
+    group = Group.objects.create(name='testgroup')
     agenda = Agenda.objects.create(label='Foobar')
-    app = login(app, username='manager', password='manager')
+    app = login(app)
 
     resp = app.get('/manage/agendas/%s/settings' % agenda.id)
     resp = resp.click('Configure', href='roles')
-    resp.form['edit_role'] = manager_user.groups.all()[0].pk
+    resp.form['edit_role'] = group.pk
     resp = resp.form.submit().follow()
-    assert 'Edit Role: Managers' in resp.text
+    assert 'Edit Role: testgroup' in resp.text
 
 
 def test_options_agenda_redirect(app, admin_user):