Fix PT compile warmup

Inadvertently broken by new dtype positional arg added to Batch.from_pb()

Author: njhill

server/text_generation_server/utils/warmup.py

@@ -52,6 +52,7 @@ def __eval_shape(batch_size: int, sequence_length: int, num_new_tokens: int, as_
         batch, errors = model.batch_type.from_pb(
             request.batch,
             tokenizer=model.tokenizer,
+            dtype=model.dtype,
             device=model.device,
             embeddings_lookup=model.word_embeddings,
             prefix_cache=model.prefix_cache,