Revert "add return_tensor parameter for feature extraction (#19257)" (#19680)

This reverts commit 35bd089a24.

tests/pipelines/test_pipelines_feature_extraction.py

@@ -15,8 +15,6 @@
 import unittest
 
 import numpy as np
-import tensorflow as tf
-import torch
 
 from transformers import (
     FEATURE_EXTRACTOR_MAPPING,
@@ -135,22 +133,6 @@ class FeatureExtractionPipelineTests(unittest.TestCase, metaclass=PipelineTestCa
                 tokenize_kwargs=tokenize_kwargs,
             )
 
-    @require_torch
-    def test_return_tensors_pt(self):
-        feature_extractor = pipeline(
-            task="feature-extraction", model="hf-internal-testing/tiny-random-distilbert", framework="pt"
-        )
-        outputs = feature_extractor("This is a test" * 100, return_tensors=True)
-        self.assertTrue(torch.is_tensor(outputs))
-
-    @require_tf
-    def test_return_tensors_tf(self):
-        feature_extractor = pipeline(
-            task="feature-extraction", model="hf-internal-testing/tiny-random-distilbert", framework="tf"
-        )
-        outputs = feature_extractor("This is a test" * 100, return_tensors=True)
-        self.assertTrue(tf.is_tensor(outputs))
-
     def get_shape(self, input_, shape=None):
         if shape is None:
             shape = []