Update comments for tokenizer changes

Signed-off-by: Alex-Brooks <[email protected]>

caikit_nlp/modules/text_generation/peft_prompt_tuning.py

@@ -35,7 +35,6 @@
 from tqdm import tqdm
 from transformers import (
     AutoModelForCausalLM,
-    DataCollatorForLanguageModeling,
     default_data_collator,
 )
 from transformers.models.auto.tokenization_auto import AutoTokenizer
@@ -890,13 +889,8 @@ def _get_collate_fn(tokenizer: AutoTokenizer, task_type: str) -> Callable:
             Callable
                 collate_fn to be used for processing batches from our datasets.
         """
-        # HACK: Do NOT use the causal LM collator (for now) because we want to set the labels ourselves...
-        # if task_type == "CAUSAL_LM":
-        #     return DataCollatorForLanguageModeling(
-        #         tokenizer=tokenizer,
-        #         return_tensors="pt",
-        #         mlm=False,
-        #     )
+        # HACK: Do NOT use the causal LM collator (for now) because
+        # want to set labels ourselves. TODO: centralize collator management.
         return default_data_collator
 
     @staticmethod
@@ -944,8 +938,7 @@ def _get_data_loaders_from_stream(
             tokenizer, max_source_length, max_target_length, verbalizer, task_ids=0
         )
         mapped_stream = train_stream.map(tokenize_function)
-        # if requires_unwrapping:
-        #     mapped_stream = mapped_stream.flatten()
+        # TODO: Deprecate and remove stream wrapper & use trainer
         wrapped_stream = SimpleIterableStreamWrapper(mapped_stream, shuffle=shuffle)
         dataloader = DataLoader(
             wrapped_stream, collate_fn=collate_fn, batch_size=batch_size