Edx platform 35175 deprecate assert dict contains subset (#36236)

* fix: replace deprecated assertDictContainsSubset with assertEqual

cms/djangoapps/api/v1/tests/test_views/test_course_runs.py

@@ -286,7 +286,7 @@ class CourseRunViewSetTests(ModuleStoreTestCase):
         data['team'] = [{'user': 'invalid-username'}]
         response = self.client.post(self.list_url, data, format='json')
         self.assertEqual(response.status_code, 400)
-        self.assertDictContainsSubset({'team': ['Course team user does not exist']}, response.data)
+        self.assertEqual(response.data.get('team'), ['Course team user does not exist'])
 
     def test_images_upload(self):
         # http://www.django-rest-framework.org/api-guide/parsers/#fileuploadparser