Remove unnecessary CPM model tests (#33621)

Remove model tests

tests/models/cpm/test_tokenization_cpm.py

@@ -12,15 +12,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import unittest
 
 from transformers.models.cpm.tokenization_cpm import CpmTokenizer
 from transformers.testing_utils import custom_tokenizers
 
-from ..xlnet.test_modeling_xlnet import XLNetModelTest
-
 
 @custom_tokenizers
-class CpmTokenizationTest(XLNetModelTest):
+class CpmTokenizationTest(unittest.TestCase):
     # There is no `CpmModel`
     def is_pipeline_test_to_skip(
         self, pipeline_test_casse_name, config_class, model_architecture, tokenizer_name, processor_name