[tests] fix "Tester object has no attribute '_testMethodName'" (#34910)

* add more cases

* fix method not found in unittest

Signed-off-by: Lin, Fanli <fanli.lin@intel.com>

* fix more cases

* add more models

* add all

* no unittest.case

* remove for oneformer

* fix style

---------

Signed-off-by: Lin, Fanli <fanli.lin@intel.com>

tests/models/conditional_detr/test_image_processing_conditional_detr.py

@@ -35,7 +35,7 @@ if is_vision_available():
     from transformers import ConditionalDetrImageProcessor
 
 
-class ConditionalDetrImageProcessingTester(unittest.TestCase):
+class ConditionalDetrImageProcessingTester:
     def __init__(
         self,
         parent,