[tests] further fix Tester object has no attribute '_testMethodName' (#35781)

* bug fix

* update with more cases

* more entries

* Fix

---------

Co-authored-by: ydshieh <ydshieh@users.noreply.github.com>

tests/models/vitmatte/test_image_processing_vitmatte.py

@@ -35,7 +35,7 @@ if is_vision_available():
     from transformers import VitMatteImageProcessor
 
 
-class VitMatteImageProcessingTester(unittest.TestCase):
+class VitMatteImageProcessingTester:
     def __init__(
         self,
         parent,
@@ -52,7 +52,6 @@ class VitMatteImageProcessingTester(unittest.TestCase):
         image_mean=[0.5, 0.5, 0.5],
         image_std=[0.5, 0.5, 0.5],
     ):
-        super().__init__()
         self.parent = parent
         self.batch_size = batch_size
         self.num_channels = num_channels