Default retry_policy to None

modal/functions.py

@@ -355,7 +355,7 @@ class _Function(typing.Generic[P, ReturnType, OriginalReturnType], _Object, type
     _build_args: dict
     _can_use_base_function: bool = False  # whether we need to call FunctionBindParams
     _is_generator: Optional[bool] = None
-    _retry_policy: Optional[api_pb2.FunctionRetryPolicy]
+    _retry_policy: Optional[api_pb2.FunctionRetryPolicy] = None
 
     # when this is the method of a class/object function, invocation of this function
     # should be using another function id and supply the method name in the FunctionInput:
@@ -524,6 +524,7 @@ def _deps():
         fun._app = class_bound_method._app
         fun._all_mounts = class_bound_method._all_mounts  # TODO: only used for mount-watching/modal serve
         fun._spec = class_bound_method._spec
+        fun._retry_policy = class_bound_method._retry_policy
         return fun
 
     @staticmethod