Fix slow backbone tests - out_indices must match stage name ordering (#28186)

Indices must match stage name ordering

tests/models/auto/test_modeling_auto.py

@@ -244,8 +244,8 @@ class AutoModelTest(unittest.TestCase):
         self.assertIsInstance(model, TimmBackbone)
 
         # Check kwargs are correctly passed to the backbone
-        model = AutoBackbone.from_pretrained("resnet18", use_timm_backbone=True, out_indices=(-1, -2))
-        self.assertEqual(model.out_indices, (-1, -2))
+        model = AutoBackbone.from_pretrained("resnet18", use_timm_backbone=True, out_indices=(-2, -1))
+        self.assertEqual(model.out_indices, (-2, -1))
 
         # Check out_features cannot be passed to Timm backbones
         with self.assertRaises(ValueError):
@@ -259,9 +259,9 @@ class AutoModelTest(unittest.TestCase):
         self.assertIsInstance(model, ResNetBackbone)
 
         # Check kwargs are correctly passed to the backbone
-        model = AutoBackbone.from_pretrained("microsoft/resnet-18", out_indices=[-1, -2])
-        self.assertEqual(model.out_indices, [-1, -2])
-        self.assertEqual(model.out_features, ["stage4", "stage3"])
+        model = AutoBackbone.from_pretrained("microsoft/resnet-18", out_indices=[-2, -1])
+        self.assertEqual(model.out_indices, [-2, -1])
+        self.assertEqual(model.out_features, ["stage3", "stage4"])
 
         model = AutoBackbone.from_pretrained("microsoft/resnet-18", out_features=["stage2", "stage4"])
         self.assertEqual(model.out_indices, [2, 4])