Add reset func to mock

Author: sjmonson

tests/unit/mock_backend.py

@@ -41,6 +41,9 @@ def model(self) -> Optional[str]:
     def info(self) -> dict[str, Any]:
         return {}
 
+    async def reset(self) -> None:
+        pass
+
     async def prepare_multiprocessing(self):
         pass