Generation tests: update imagegpt input name, remove unused functions (#33663)

tests/models/gpt_bigcode/test_modeling_gpt_bigcode.py

@@ -22,7 +22,7 @@ from transformers.testing_utils import require_torch, slow, torch_device
 
 from ...generation.test_utils import GenerationTesterMixin
 from ...test_configuration_common import ConfigTester
-from ...test_modeling_common import ModelTesterMixin, floats_tensor, ids_tensor, random_attention_mask
+from ...test_modeling_common import ModelTesterMixin, ids_tensor, random_attention_mask
 from ...test_pipeline_mixin import PipelineTesterMixin
 
 
@@ -178,35 +178,6 @@ class GPTBigCodeModelTester:
         config.vocab_size = 300
         return config
 
-    def prepare_config_and_inputs_for_decoder(self):
-        (
-            config,
-            input_ids,
-            input_mask,
-            head_mask,
-            token_type_ids,
-            mc_token_ids,
-            sequence_labels,
-            token_labels,
-            choice_labels,
-        ) = self.prepare_config_and_inputs()
-
-        encoder_hidden_states = floats_tensor([self.batch_size, self.seq_length, self.hidden_size])
-        encoder_attention_mask = ids_tensor([self.batch_size, self.seq_length], vocab_size=2)
-
-        return (
-            config,
-            input_ids,
-            input_mask,
-            head_mask,
-            token_type_ids,
-            sequence_labels,
-            token_labels,
-            choice_labels,
-            encoder_hidden_states,
-            encoder_attention_mask,
-        )
-
     def create_and_check_gpt_bigcode_model(self, config, input_ids, input_mask, head_mask, token_type_ids, *args):
         model = GPTBigCodeModel(config=config)
         model.to(torch_device)