fix: remove Optional types to pass openenv validate

inference.py

@@ -83,7 +83,7 @@ async def run_task(env, task_id):
             method=str(fixed.get("method", "GET")),
             url=str(fixed.get("url", obs.broken_request.get("url", "/mock_api/users"))),
             headers=dict(fixed.get("headers") or {}),
-            body=fixed.get("body"),
+            body=fixed.get("body") or {},
             query_params=dict(fixed.get("query_params") or {}),
         )
 

models.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 try:
     from openenv.core.env_server.types import Action, Observation, State
 except ImportError:
@@ -7,14 +9,13 @@ except ImportError:
         from openenv.core.env_server import Action, Observation, State
 
 from pydantic import Field
-from typing import Any
 
 
 class APIAction(Action):
     method: str = Field(default="GET")
     url: str = Field(default="/mock_api/users")
     headers: dict = Field(default_factory=dict)
-    body: Any = Field(default=None)
+    body: dict = Field(default_factory=dict)
     query_params: dict = Field(default_factory=dict)