Updating requirements.txt

backend/requirements.txt

@@ -40,9 +40,10 @@ langchain-community==0.2.12
 langchain-chroma==0.1.4
 
 fake-useragent==1.5.1
-chromadb==0.5.15
-pymilvus==2.4.7
+chromadb==0.5.5
+pymilvus==2.4.6
 qdrant-client~=1.12.0
+opensearch-py==2.7.1
 
 sentence-transformers==3.2.0
 colbert-ai==0.2.21