[AuraFlow] fix long prompt handling (#8937)

fix

src/diffusers/pipelines/aura_flow/pipeline_aura_flow.py

@@ -260,7 +260,6 @@ class AuraFlowPipeline(DiffusionPipeline):
                 padding="max_length",
                 return_tensors="pt",
             )
-            text_inputs = {k: v.to(device) for k, v in text_inputs.items()}
             text_input_ids = text_inputs["input_ids"]
             untruncated_ids = self.tokenizer(prompt, padding="longest", return_tensors="pt").input_ids
 
@@ -273,6 +272,7 @@ class AuraFlowPipeline(DiffusionPipeline):
                     f" {max_length} tokens: {removed_text}"
                 )
 
+            text_inputs = {k: v.to(device) for k, v in text_inputs.items()}
             prompt_embeds = self.text_encoder(**text_inputs)[0]
             prompt_attention_mask = text_inputs["attention_mask"].unsqueeze(-1).expand(prompt_embeds.shape)
             prompt_embeds = prompt_embeds * prompt_attention_mask