Update modeling_custom_t5.py

modeling_custom_t5.py

@@ -27,6 +27,7 @@ from .configuration_custom_t5 import (
     POSITION_ENCODING_ALiBi_LEARNED,
     POSITION_ENCODING_NONE,
     POSITION_ENCODING_NONE_WINDOW,
+    CustomT5Config,
 )
 from .modeling_t5 import (
     T5Stack,
@@ -1181,6 +1182,7 @@ class CustomT5Stack(T5Stack):
 
 
 class CustomDecoderOnlyT5(T5PreTrainedModel):
+    config_class = CustomT5Config
     _keys_to_ignore_on_load_missing = [
         r"decoder\.embed_tokens\.weight",
         r"encoder",