refactor: replace print statements with logging for better error tracking

backend/open_webui/retrieval/vector/dbs/chroma.py

@@ -1,4 +1,5 @@
 import chromadb
+import logging
 from chromadb import Settings
 from chromadb.utils.batch_utils import create_batches
 
@@ -16,6 +17,10 @@ from open_webui.config import (
     CHROMA_CLIENT_AUTH_PROVIDER,
     CHROMA_CLIENT_AUTH_CREDENTIALS,
 )
+from open_webui.env import SRC_LOG_LEVELS
+
+log = logging.getLogger(__name__)
+log.setLevel(SRC_LOG_LEVELS["RAG"])
 
 
 class ChromaClient:
@@ -103,7 +108,7 @@ class ChromaClient:
                 )
             return None
         except Exception as e:
-            print(e)
+            log.exception(f"Error querying collection {collection} with limit {limit}: {e}")
             return None
 
     def get(self, collection_name: str) -> Optional[GetResult]: