community[patch]: milvus will autoflush, manual flush is slowly (#19300)

reference:


https://milvus.io/docs/configure_quota_limits.md#quotaAndLimitsflushRateenabled

https://github.com/milvus-io/milvus/issues/31407

Co-authored-by: Bagatur <22008038+baskaryan@users.noreply.github.com>

libs/community/langchain_community/vectorstores/milvus.py

@@ -611,7 +611,6 @@ class Milvus(VectorStore):
                     "Failed to insert batch starting at entity: %s/%s", i, total_count
                 )
                 raise e
-        self.col.flush()
         return pks
 
     def similarity_search(