Watermark: fix tests (#30961)

* fix tests

* style

* Update tests/generation/test_utils.py
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>

---------
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>

tests/generation/test_utils.py

@@ -2148,6 +2148,8 @@ class GenerationIntegrationTests(unittest.TestCase, GenerationIntegrationTestsMi
         watermark_config = WatermarkingConfig(bias=2.5, seeding_scheme="selfhash")
         _ = model.generate(**model_inputs, watermarking_config=watermark_config, do_sample=False, max_length=15)
 
+        # We will not check watermarked text, since we check it in `logits_processors` tests
+        # Checking if generated ids are as expected fails on different hardware
         args = {
             "bias": 2.0,
             "context_width": 1,
@@ -2158,19 +2160,11 @@ class GenerationIntegrationTests(unittest.TestCase, GenerationIntegrationTestsMi
         output = model.generate(**model_inputs, do_sample=False, max_length=15)
         output_selfhash = model.generate(**model_inputs, watermarking_config=args, do_sample=False, max_length=15)
 
-        # check that the watermarked text is generating what is should
-        self.assertListEqual(
-            output.tolist(), [[40, 481, 307, 262, 717, 284, 9159, 326, 314, 716, 407, 257, 4336, 286, 262]]
-        )
-        self.assertListEqual(
-            output_selfhash.tolist(), [[40, 481, 307, 2263, 616, 640, 284, 651, 616, 1621, 503, 612, 553, 531, 367]]
-        )
-
+        # Check that the detector is detecting watermarked text
         detector = WatermarkDetector(model_config=model.config, device=torch_device, watermarking_config=args)
         detection_out_watermarked = detector(output_selfhash[:, input_len:], return_dict=True)
         detection_out = detector(output[:, input_len:], return_dict=True)
 
-        # check that the detector is detecting watermarked text
         self.assertListEqual(detection_out_watermarked.prediction.tolist(), [True])
         self.assertListEqual(detection_out.prediction.tolist(), [False])