Import rag_tokenizer in function to fix ruff check issue

rag/nlp/__init__.py

@@ -266,6 +266,7 @@ def is_chinese(text):
 
 
 def tokenize(d, txt, eng):
+    from . import rag_tokenizer
     d["content_with_weight"] = txt
     t = re.sub(r"</?(table|td|caption|tr|th)( [^<>]{0,12})?>", " ", txt)
     d["content_ltks"] = rag_tokenizer.tokenize(t)
@@ -363,6 +364,7 @@ def attach_media_context(chunks, table_context_size=0, image_context_size=0):
     Best-effort ordering: if positional info exists on any chunk, use it to
     order chunks before collecting context; otherwise keep original order.
     """
+    from . import rag_tokenizer
     if not chunks or (table_context_size <= 0 and image_context_size <= 0):
         return chunks