Update retrieval.py

retrieval.py

@@ -79,10 +79,10 @@ class EmbedFunction:
 EMBED_MODEL_NAME = "sentence-transformers/all-MiniLM-L6-v2"
 embed_function = EmbedFunction(EMBED_MODEL_NAME)
 
-# Use in-memory storage to avoid persistent storage issues.
+# Use ephemeral (in-memory) storage to avoid persistent storage issues.
 client = chromadb.Client(
     settings=Settings(
-        persist_directory=":memory:",
+        in_memory=True,
         anonymized_telemetry=False
     )
 )