Fix tests broken in recent commits (#1239)

We'll have good CI soon...

## Test Plan

### Automated Testing
Wroks

src/exo/worker/tests/unittests/test_mlx/conftest.py

@@ -19,7 +19,7 @@ from exo.shared.types.tasks import ChatCompletionTaskParams
 from exo.shared.types.worker.shards import PipelineShardMetadata, TensorShardMetadata
 from exo.worker.engines.mlx import Model
 from exo.worker.engines.mlx.generator.generate import mlx_generate
-from exo.worker.engines.mlx.utils_mlx import shard_and_load
+from exo.worker.engines.mlx.utils_mlx import apply_chat_template, shard_and_load
 
 
 class MockLayer(nn.Module):
@@ -119,11 +119,12 @@ def run_gpt_oss_pipeline_device(
             max_tokens=max_tokens,
         )
 
+        prompt = apply_chat_template(tokenizer, task)
+
         generated_text = ""
+
         for response in mlx_generate(
-            model=model,
-            tokenizer=tokenizer,
-            task=task,
+            model=model, tokenizer=tokenizer, task=task, prompt=prompt
         ):
             generated_text += response.text
             if response.finish_reason is not None:
@@ -186,11 +187,14 @@ def run_gpt_oss_tensor_parallel_device(
             max_tokens=max_tokens,
         )
 
+        prompt = apply_chat_template(tokenizer, task)
+
         generated_text = ""
         for response in mlx_generate(
             model=model,
             tokenizer=tokenizer,
             task=task,
+            prompt=prompt,
         ):
             generated_text += response.text
             if response.finish_reason is not None:

src/exo/worker/tests/unittests/test_mlx/test_tokenizers.py

@@ -105,7 +105,7 @@ def event_loop():
     TEST_MODELS,
 )
 @pytest.mark.asyncio
-async def test_tokenizer_encode_decode(short_id: str, model_card: ModelCard) -> None:
+async def test_tokenizer_encode_decode(model_card: ModelCard) -> None:
     """Test that tokenizer can encode and decode text correctly."""
     model_id = model_card.model_id
 
@@ -170,9 +170,7 @@ async def test_tokenizer_encode_decode(short_id: str, model_card: ModelCard) ->
     TEST_MODELS,
 )
 @pytest.mark.asyncio
-async def test_tokenizer_has_required_attributes(
-    short_id: str, model_card: ModelCard
-) -> None:
+async def test_tokenizer_has_required_attributes(model_card: ModelCard) -> None:
     """Test that tokenizer has required attributes for inference."""
     model_id = model_card.model_id