Pipeline testing - using tiny models on Hub (#20426)

* rework pipeline tests

* run pipeline tests

* fix

* fix

* fix

* revert the changes in get_test_pipeline() parameter list

* fix expected error message

* skip a test

* clean up

---------

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

tests/pipelines/test_pipelines_text_generation.py

@@ -143,7 +143,7 @@ class TextGenerationPipelineTests(unittest.TestCase, metaclass=PipelineTestCaseM
             ],
         )
 
-    def get_test_pipeline(self, model, tokenizer, feature_extractor, image_processor):
+    def get_test_pipeline(self, model, tokenizer, processor):
         text_generator = TextGenerationPipeline(model=model, tokenizer=tokenizer)
         return text_generator, ["This is a test", "Another test"]