Update linode_api4/objects/monitor.py

Co-authored-by: Ye Chen <127243817+yec-akamai@users.noreply.github.com>

Author: srbhaakamai

linode_api4/objects/monitor.py

@@ -280,7 +280,7 @@ class RuleCriteria(JSONObject):
       "rule_criteria": { "rules": [ { ... }, ... ] }
     """
 
-    rules: List[Rule] = field(default_factory=list)
+    rules: List[Rule] = None
 
 
 @dataclass