remove drops unused

lightrag/kg/mongo_impl.py

@@ -117,11 +117,6 @@ class MongoKVStorage(BaseKVStorage):
         # Mongo handles persistence automatically
         pass
 
-    async def drop(self) -> None:
-        """Drop the collection"""
-        await self._data.drop()
-
-
 @final
 @dataclass
 class MongoDocStatusStorage(DocStatusStorage):
@@ -169,10 +164,6 @@ class MongoDocStatusStorage(DocStatusStorage):
             )
         await asyncio.gather(*update_tasks)
 
-    async def drop(self) -> None:
-        """Drop the collection"""
-        await self._data.drop()
-
     async def get_status_counts(self) -> dict[str, int]:
         """Get counts of documents in each status"""
         pipeline = [{"$group": {"_id": "$status", "count": {"$sum": 1}}}]