feat:修改generate_long的并发逻辑

fish_speech/models/text2semantic/inference.py

@@ -995,7 +995,7 @@ def generate_long_batched(
 
         results = {}
 
-        with ThreadPoolExecutor(max_workers=3) as executor:
+        with ThreadPoolExecutor(max_workers=min(3, len(batches))) as executor:
             futures = [
                 executor.submit(run_one_batch, i, b)
                 for i, b in enumerate(batches)