LongCat Image pipeline: Allow offloading/quantization of text_encoder component (#12963)

* Don't attempt to move the text_encoder. Just move the generated_ids.

* The inputs to the text_encoder should be on its device

Author: Yahweasel

src/diffusers/pipelines/longcat_image/pipeline_longcat_image.py

@@ -260,10 +260,10 @@ def rewire_prompt(self, prompt, device):
             text = self.text_processor.apply_chat_template(message, tokenize=False, add_generation_prompt=True)
             all_text.append(text)
 
-        inputs = self.text_processor(text=all_text, padding=True, return_tensors="pt").to(device)
+        inputs = self.text_processor(text=all_text, padding=True, return_tensors="pt").to(self.text_encoder.device)
 
-        self.text_encoder.to(device)
         generated_ids = self.text_encoder.generate(**inputs, max_new_tokens=self.tokenizer_max_length)
+        generated_ids.to(device)
         generated_ids_trimmed = [out_ids[len(in_ids) :] for in_ids, out_ids in zip(inputs.input_ids, generated_ids)]
         output_text = self.text_processor.batch_decode(
             generated_ids_trimmed, skip_special_tokens=True, clean_up_tokenization_spaces=False