community[patch]: Implement Unique ID Enforcement in FAISS (#17244)

**Description:**
Implemented unique ID validation in the FAISS component to ensure all
document IDs are distinct. This update resolves issues related to
non-unique IDs, such as inconsistent behavior during deletion processes.

libs/community/langchain_community/vectorstores/faiss.py

@@ -190,6 +190,9 @@ class FAISS(VectorStore):
         _len_check_if_sized(documents, embeddings, "documents", "embeddings")
         _len_check_if_sized(documents, ids, "documents", "ids")
 
+        if ids and len(ids) != len(set(ids)):
+            raise ValueError("Duplicate ids found in the ids list.")
+
         # Add to the index.
         vector = np.array(embeddings, dtype=np.float32)
         if self._normalize_L2: