Mark pipeline tests to skip them easily (#21887)

* Mark pipeline tests to skip them easily

* Mark the mixin as pipeline test

* Update src/transformers/testing_utils.py

Co-authored-by: Yih-Dar <2521628+ydshieh@users.noreply.github.com>

---------

Co-authored-by: Yih-Dar <2521628+ydshieh@users.noreply.github.com>

tests/pipelines/test_pipelines_depth_estimation.py

@@ -17,7 +17,15 @@ import unittest
 
 from transformers import MODEL_FOR_DEPTH_ESTIMATION_MAPPING, is_torch_available, is_vision_available
 from transformers.pipelines import DepthEstimationPipeline, pipeline
-from transformers.testing_utils import nested_simplify, require_tf, require_timm, require_torch, require_vision, slow
+from transformers.testing_utils import (
+    is_pipeline_test,
+    nested_simplify,
+    require_tf,
+    require_timm,
+    require_torch,
+    require_vision,
+    slow,
+)
 
 from .test_pipelines_common import ANY
 
@@ -40,6 +48,7 @@ def hashimage(image: Image) -> str:
     return m.hexdigest()
 
 
+@is_pipeline_test
 @require_vision
 @require_timm
 @require_torch