Fix init for MT5 (#8591)

src/transformers/__init__.py

@@ -145,6 +145,7 @@ from .models.marian import MarianConfig
 from .models.mbart import MBartConfig
 from .models.mmbt import MMBTConfig
 from .models.mobilebert import MOBILEBERT_PRETRAINED_CONFIG_ARCHIVE_MAP, MobileBertConfig, MobileBertTokenizer
+from .models.mt5 import MT5Config
 from .models.openai import OPENAI_GPT_PRETRAINED_CONFIG_ARCHIVE_MAP, OpenAIGPTConfig, OpenAIGPTTokenizer
 from .models.pegasus import PegasusConfig
 from .models.phobert import PhobertTokenizer
@@ -498,7 +499,7 @@ if is_torch_available():
         MobileBertPreTrainedModel,
         load_tf_weights_in_mobilebert,
     )
-    from .models.mt5 import MT5Config, MT5ForConditionalGeneration, MT5Model
+    from .models.mt5 import MT5ForConditionalGeneration, MT5Model
     from .models.openai import (
         OPENAI_GPT_PRETRAINED_MODEL_ARCHIVE_LIST,
         OpenAIGPTDoubleHeadsModel,

src/transformers/utils/dummy_pt_objects.py

@@ -1361,11 +1361,6 @@ def load_tf_weights_in_mobilebert(*args, **kwargs):
     requires_pytorch(load_tf_weights_in_mobilebert)
 
 
-class MT5Config:
-    def __init__(self, *args, **kwargs):
-        requires_pytorch(self)
-
-
 class MT5ForConditionalGeneration:
     def __init__(self, *args, **kwargs):
         requires_pytorch(self)