fix: when delete knowledge, error: space list error embedding is requ…

…ired for MilvusStore (#1359)

Co-authored-by: xiuzhu <edy@dodge-pro.local>

dbgpt/storage/vector_store/milvus_store.py

@@ -175,9 +175,6 @@ def __init__(self, vector_store_config: MilvusVectorConfig) -> None:
             hex_str = bytes_str.hex()
             self.collection_name = hex_str
 
-        if not vector_store_config.embedding_fn:
-            raise ValueError("embedding is required for MilvusStore")
-
         self.embedding: Embeddings = vector_store_config.embedding_fn
         self.fields: List = []
         self.alias = milvus_vector_config.get("alias") or "default"